What Would The Sun Looks Like Viewing From Every Planet In Our Solar System

How the moon reveals the sun's mass | Astronomy Essentials | EarthSky

What does the sun look like from other planets? Given the vast and disparate distances, it is not so easy to imagine.

But the digital renderings created by Ron Miller, a Virginia-based illustrator who has spent decades representing space, help answer this delicate question. They show the sun as it appears in the sky of each of the nine planets (along with our favorite dwarf planet, Pluto).

“I’ve taken care in not only making sure the Sun is depicted realistically, but also the surfaces of the planets and satellites as well,” Miller told IFLScience.

Scroll down to see Miller’s starkly beautiful images…

Mercury

The sun as seen from Mercury, which is about 60 million kilometers from the sun or 39 percent of the distance from Earth to the sun. On Mercury, the sun is about three times larger than on Earth.

Venus

The sun as seen (almost) from Venus, about 108 million kilometers from the sun (72% of the distance from Earth to the sun). Seen from beneath Venus’ dense, sulfuric acid-laden clouds, the sun is no more than a dimly glowing patch in the perpetual overcast.

Earth

Earth, which is 150 million kilometers (93 million miles) from the Sun. If you’ve ever seen a solar eclipse, this sight will be very familiar to you

 

Mars

Mars orbits the Sun at a distance of 230 million kilometers, or about 1.5 times further than Earth. But it is not the distance that reduces the visibility of the Sun, but the strong winds that carry dust up into the outer confines of atmosphere of the red planet.

Jupiter

This is what the Sun looks like from Europa, one Jupiter’s moons. It is much, much further away, at 779 million kilometers from the Sun (5.2 times greater than the distance between the Sun and the Earth).

Saturn

The sun as seen from Saturn, about 1.5 billion kilometers from the sun. It is about 9.5 times farther than the distance from Earth to the sun. Here, water and gas crystals, including ammonia, refract sunlight, creating beautiful optical effects such as haloes and sundogs.

Uranus

The sun as seen from Ariel, one of Uranus’s moons. Uranus is about 2.9 billion kilometers from the sun, or about 19 times farther than the distance from Earth to the sun.

Neptune

The sun as seen from Triton, one of Neptune’s moons. Neptune is about 4.5 billion kilometers from the sun. That’s about 30 times farther than the distance from Earth to the sun.

Pluto

 

From the perspective of the planet furthest from our solar system, the Sun is little more than a tiny point of light. Pluto is 6 billion kilometers from the Sun (40 times the distance between it and Earth), which means that the light reaching it is 1600 times weaker than that which we receive here.

How big is the Sun? What Is the Biggest Star?

Our Sun is a normal main-sequence G2 star, one of more than 100 billion stars in our galaxy but although The sun may appear to be the largest star in the sky, that’s just because it’s the closest. On a stellar scale, it’s really quite average — about half of the known stars are larger; half are smaller. The largest known star in the universe is UY Scuti, a hypergiant with a radius around 1,700 times larger than the sun. And it’s not alone in dwarfing Earth’s dominant star.

The largest of all

In 1860, German astronomers at the Bonn Observatory first cataloged UY Scuti, naming it BD -12 5055. During a second detection, the astronomers realized it grows brighter and dimmer over a 740-day period, leading astronomers to classify it as a variable star. The star lies near the center of the Milky Way, roughly 9,500 light-years away.

Located in the constellation Scutum, UY Scuti is a hypergiant, the classification that comes after supergiant, which itself comes after giant. Hypergiants are rare stars that shine very brightly. They lose much of their mass through fast-moving stellar winds.

Of course, all stellar sizes are estimates, based on measurements taken from far away.

UY Scuti largest known star

“The complication with stars is that they have diffuse edges,” wrote astronomer Jillian Scudder of the University of Sussex. “Most stars don’t have a rigid surface where the gas ends and vacuum begins, which would have served as a harsh dividing line and easy marker of the end of the star.”

Instead, astronomers rely on a star’s photosphere, where the star becomes transparent to light and the particles of light, or photons, can escape the star.

“As far as an astrophysicist is concerned, this is the surface of the star, as this is the point at which photons can leave the star,” Scudder said.

If UY Scuti replaced the sun in the center of the solar system, its photosphere would extend just beyond the orbit of Jupiter. The nebula of gas stripped from the star extends even farther out, beyond the orbit of Pluto to 400 times time the Earth-sun distance.

But UY Scuti doesn’t remain stagnant. Scudder pointed out that the star varies in brightness as it varies in radius, with a margin of error of about 192 solar radii. These errors could allow other stars to beat out UY Scuti in the race for size. In fact, there are as many as 30 stars whose radii fit within UY Scuti’s smallest estimated size, so it shouldn’t sit too securely on its throne.

Nor does UY Scuti’s large radius make it the most massive star. That honor goes to R136a1, which weighs in at about 300 times the mass of the sun but only about 30 solar radii. UY Scuti, in comparison, is only about 30 times more massive than the sun.

NASA’s Hubble Space Telescope reveals the supercluster Westerlund 1, home of one of the largest known stars. Westerlund 1-26, a red supergiant, has a radius more than 1,500 times that of the sun. (Image credit: ESA/Hubble & NASA)

Title contenders

So which star would take UY Scuti’s place if it weren’t exactly 1,708 solar radii? Here are a few of the stars that might dominate:

  • WOH G64, measuring 1,504 to 1,730 solar radii. It is a red hypergiant star in the Large Magellanic Cloud (a satellite galaxy to the Milky Way). Like UY Scuti, it varies in brightness. Some estimates have placed its radius as high as 3,000 solar radii. Variations are due in part to the presence of dust, which affects the brightness of the star and its related radius.
  • RW Cephei, at 1,535 solar radii. This star is an orange hypergiant in the constellation of Cepheus, and also a variable star.
  • Westerlund 1-26, which comes in at 1,530 to 2,550 solar radii. If the upper estimate is correct, its photosphere would engulf the orbit of Saturn if the star were placed at the center of the solar system. The star changes its temperature but not its brightness.
  • KY Cygni, at 1,420 to 2,850 solar radii. It’s a red supergiant in the constellation Cygnus. The upper estimate is considered by astronomers to be dubious due to an observational error, while the lower estimate is consistent with other stars from the same survey, as well as theoretical models of stellar evolution.
  • VY Canis Majoris, ranging from 1,300 to 1,540 solar radii. This red hypergiant star was previously estimated to be 1,800 to 2,200 solar radii, but that size put it outside the bounds of stellar evolutionary theory. New measurements brought it down to size. (Some sources still list it as the largest star.)
  • History of The Sun

    The Sun is by far the largest object in the solar system. It contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest).

    It is often said that the Sun is an “ordinary” star. That’s true in the sense that there are many others similar to it. But there are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun.

    The Sun is personified in many mythologies: the Greeks called it Helios and the Romans called it Sol.

    The Sun is, at present, about 70% hydrogen and 28% helium by mass everything else (“metals”) amounts to less than 2%. This changes slowly over time as the Sun converts hydrogen to helium in its core.

    The outer layers of the Sun exhibit differential rotation: at the equator the surface rotates once every 25.4 days; near the poles it’s as much as 36 days. This odd behavior is due to the fact that the Sun is not a solid body like the Earth. Similar effects are seen in the gas planets. The differential rotation extends considerably down into the interior of the Sun but the core of the Sun rotates as a solid body.

    Conditions at the Sun’s core (approximately the inner 25% of its radius) are extreme. The temperature is 15.6 million Kelvin and the pressure is 250 billion atmospheres. At the center of the core the Sun’s density is more than 150 times that of water.

    The Sun’s power (about 386 billion billion mega Watts) is produced by nuclear fusion reactions. Each second about 700,000,000 tons of hydrogen are converted to about 695,000,000 tons of helium and 5,000,000 tons (=3.86e33 ergs) of energy in the form of gamma rays. As it travels out toward the surface, the energy is continuously absorbed and re-emitted at lower and lower temperatures so that by the time it reaches the surface, it is primarily visible light. For the last 20% of the way to the surface the energy is carried more by convection than by radiation.

    The surface of the Sun, called the photosphere, is at a temperature of about 5800 K. Sunspots are “cool” regions, only 3800 K (they look dark only by comparison with the surrounding regions). Sunspots can be very large, as much as 50,000 km in diameter. Sunspots are caused by complicated and not very well understood interactions with the Sun’s magnetic field.

    A small region known as the chromosphere lies above the photosphere.

    The highly rarefied region above the chromosphere, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K.

    It just happens that the Moon and the Sun appear the same size in the sky as viewed from the Earth. And since the Moon orbits the Earth in approximately the same plane as the Earth’s orbit around the Sun sometimes the Moon comes directly between the Earth and the Sun. This is called a solar eclipse; if the alignment is slighly imperfect then the Moon covers only part of the Sun’s disk and the event is called a partial eclipse. When it lines up perfectly the entire solar disk is blocked and it is called a total eclipse of the Sun. Partial eclipses are visible over a wide area of the Earth but the region from which a total eclipse is visible, called the path of totality, is very narrow, just a few kilometers (though it is usually thousands of kilometers long). Eclipses of the Sun happen once or twice a year. If you stay home, you’re likely to see a partial eclipse several times per decade. But since the path of totality is so small it is very unlikely that it will cross you home. So people often travel half way around the world just to see a total solar eclipse. To stand in the shadow of the Moon is an awesome experience. For a few precious minutes it gets dark in the middle of the day. The stars come out. The animals and birds think it’s time to sleep. And you can see the solar corona. It is well worth a major journey.

    The Sun’s magnetic field is very strong (by terrestrial standards) and very complicated. Its magnetosphere (also known as the heliosphere) extends well beyond Pluto.

    In addition to heat and light, the Sun also emits a low density stream of charged particles (mostly electrons and protons) known as the solar wind which propagates throughout the solar system at about 450 km/sec. The solar wind and the much higher energy particles ejected by solar flares can have dramatic effects on the Earth ranging from power line surges to radio interference to the beautiful aurora borealis.

    Recent data from the spacecraft Ulysses show that during the minimum of the solar cycle the solar wind emanating from the polar regions flows at nearly double the rate, 750 kilometers per second, than it does at lower latitudes. The composition of the solar wind also appears to differ in the polar regions. During the solar maximum, however, the solar wind moves at an intermediate speed.

    Further study of the solar wind will be done by Wind, ACE and SOHO spacecraft from the dynamically stable vantage point directly between the Earth and the Sun about 1.6 million km from Earth.

    The solar wind has large effects on the tails of comets and even has measurable effects on the trajectories of spacecraft.

    Spectacular loops and prominences are often visible on the Sun’s limb (left).

    The Sun’s output is not entirely constant. Nor is the amount of sunspot activity. There was a period of very low sunspot activity in the latter half of the 17th century called the Maunder Minimum. It coincides with an abnormally cold period in northern Europe sometimes known as the Little Ice Age. Since the formation of the solar system the Sun’s output has increased by about 40%.

    The Sun is about 4.5 billion years old. Since its birth it has used up about half of the hydrogen in its core. It will continue to radiate “peacefully” for another 5 billion years or so (although its luminosity will approximately double in that time). But eventually it will run out of hydrogen fuel. It will then be forced into radical changes which, though commonplace by stellar standards, will result in the total destruction of the Earth (and probably the creation of a planetary nebula).

    The Sun’s satellites

    There are eight planets and a large number of smaller objects orbiting the Sun. (Exactly which bodies should be classified as planets and which as “smaller objects” has been the source of some controversy, but in the end it is really only a matter of definition. Pluto is no longer officially a planet but we’ll keep it here for history’s sake.)

    Planet Distance(000 km) Radius(km) Mass(kg) Discoverer Date
    Mercury 57,910 2439 3.30e23
    Venus 108,200 6052 4.87e24
    Earth 149,600 6378 5.98e24
    Mars 227,940 3397 6.42e23
    Jupiter 778,330 71492 1.90e27
    Saturn 1,426,940 60268 5.69e26
    Uranus 2,870,990 25559 8.69e25 Herschel 1781
    Neptune 4,497,070 24764 1.02e26 Galle 1846
    Pluto 5,913,520 1160 1.31e22 Tombaugh 1930

    More detailed data and definitions of terms can be found on the data page.

    More about the Sun

      • more Sun images
      • from NSSDC
      • Stanford Solar Center
      • Yohkoh Public Outreach Project, lots of good info, images and movies
      • The University of Michigan Solar and Heliospheric Research Group’s Web Space for Kids and Non-Scientists
      • Solar Data Analysis Center
      • Elemental abundances in the Sun
      • National Solar Observatory / Sacramento Peak Image Index
      • more info and links about sunspots
      • historical info about sunspots
      • Virtual Tour of the Sun by Michael Berger
      • The Sun: a Pictorial Introduction, a slide set by P. Charbonneau and O.R. White
      • The HK Project
      • Ulysses Home Page
      • Spartan 201, NASA’s mission to explore the Sun’s corona
      • IACG Campaign IV: including lots of good references

    Open Issues

    • Is there a causal connection between the Maunder Minimum and the Little Ice Age or was it just a coincidence? How does the variability of the Sun affect the Earth’s climate?
    • Since all the planets except Pluto orbit the Sun within a few degrees of the plane of the Sun’s equator, we know very little about the interplanetary environment outside that plane. The Ulysses mission will provide information about the polar regions of the Sun.
    • The corona is much hotter than the photosphere. Why?

    Interesting Facts about the Sun

      • The Sun is one of the millions of stars in the solar system. It is, however, larger than most (although not the biggest) and a very special star to us. Without the Sun there would be absolutely no life on Earth.
      • The Sun is 870,000 miles (1.4 million kilometers) across. This is so big it is hard to imagine, but it would take more than one million Earths to fill the size of the Sun!
      • The Sun is so big it takes up 99% of the matter in our solar system. The 1% left over is taken up by planets, asteroids, moons and other matter.
      • The Sun is about 4.5 billion years old. It is thought to be halfway through its lifetime. Stars get bigger as they get older.
      • As the Sun ages, it will get bigger. When this happens, it will consume some of the things close to it, and this includes Mercury, Venus and maybe even Earth and Mars. Luckily this is billions of years in the future.
      • The Sun is the centre of the solar system.
      • The Sun is 92.96 million miles (149.6 kilometers) away from Earth.
      • The Sun is made of a ball of burning gases. These gases are 92.1% hydrogen and 7.8% helium.
    • The sunlight we see on Earth left the Sun 8 minutes ago. This is the length of time it takes for the light to travel the distance between the Sun and the Earth.
    • When the moon goes around the Earth, it sometimes finds itself between the Earth and the Sun. This is called a solar eclipse and makes the Earth dark whilst the moon shuts out most of the Sun’s light. This only lasts for a couple of hours while the moon continues its rotation and moves out of the way of the sun.
    • In ancient astronomy, it was thought that the Sun moved. People believed that the Earth stayed still and the Sun rotated around it.
    • About 2000 years ago some began to think it was the Sun that stays still whilst the planets make a path around it. This only became an accepted theory around the 1600s when Isaac Newton proposed the sun-centric solar system.
    • The Sun is almost a perfect sphere. It is the closest thing to a sphere found in nature with only a 6.2 mile (10 kilometres) difference between its vertical and horizontal measurements.
    • The Sun’s core is extremely hot! An unthinkable 13,600,000 degrees Celcius!
    • The Sun has a very big magnetic field. It is the most powerful magnetic field in the whole solar system. This field is regenerating itself, but scientists are unsure how.
    • The Sun produces solar winds. These are a stream of particles from the Sun that stream out into space. This is why planets atmospheres are so important. They protect the planet from these solar winds.
    • The Sun rotates but not as Earth does. On Earth, the planet is rotating at the same speed no matter where you are. The Sun does not rotate like a solid object and is spinning faster at its equator than it is at its poles. It is complicated to say how fast the Sun is spinning but depending whereabouts on the Sun you are looking at it takes between 24 and 38 days to spin around.
    • The Sun has been both worshipped and feared throughout history by a variety of cultures.

ASTEROID experts have produced a terrifying simulation Comparing the Size of Asteroids in our Solar System to New York City .

The Absolutely Frightening apocalyptic consequences of a colossal space rock colliding with Earth.

Comparison of asteroid sizes

Asteroids are rocky worlds revolving around the sun that are too small to be called planets. They are also known as planetoids or minor planets. There are millions of asteroids, ranging in size from hundreds of miles to several feet across. In total, the mass of all the asteroids is less than that of Earth’s moon.

Despite their size, asteroids can be dangerous. Many have hit Earth in the past, and more will crash into our planet in the future. That’s one reason scientists study asteroids and are eager to learn more about their numbers, orbits and physical characteristics. If an asteroid is headed our way, we want to know that.

The video begins by comparing a human to one of the minor planets before revealing their enormity as the following asteroids quickly dwarf New York City in its entirety. It comes out with asteroid 2008 TC3, which is around 4.1 meters in diameter.

Things take a dramatic turn when asteroid 99942 Apophis steps onto the scene with an average diameter of 370 meters. Then it goes all the way up to 1 Ceres (which is 939km in diameter) and takes up a large chunk of the US.

Stephen Hawking in his last book, Brief Answers to the Big Questions, wrote that asteroids are the biggest threat to Earth. If any of these hit the Earth it would be devastating.

Formation

Asteroids are leftovers from the formation of our solar system about 4.6 billion years ago. Early on, the birth of Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, causing the small objects that were there to collide with each other and fragment into the asteroids seen today.

Understanding of how the solar system evolved is constantly expanding. Two fairly recent theories, the Nice model and the Grand Tack, suggest that the gas giants moved around before settling into their modern orbits. This movement could have sent asteroids from the main belt raining down on the terrestrial planets, emptying and refilling the original belt.

Physical characteristics

Asteroids can reach as large as Ceres, which is 940 kilometers (about 583 miles) across. On the other end of the scale, the smallest asteroid ever studied is the 6-foot-wide (2 meters) space rock 2015 TC25, which was observed when it made a close flyby of Earth in October 2015. The chances of it hitting Earth in the foreseeable future are small, Vishnu Reddy of the University of Arizona’s Lunar and Planetary Laboratory said in a statement.

“You can think of [an asteroid] as a meteorite floating in space that hasn’t hit the atmosphere and made it to the ground — yet,” Reddy added.

Nearly all asteroids are irregularly shaped, although a few of the largest are nearly spherical, such as Ceres. They are often pitted or cratered — for instance, Vesta has a giant crater some 285 miles (460 km) in diameter. The surfaces of most asteroids are thought to be covered in dust.

As asteroids revolve around the sun in elliptical orbits, they rotate, sometimes tumbling quite erratically. More than 150 asteroids are also known to have a small companion moon, with some having two moons. Binary or double asteroids also exist, in which two asteroids of roughly equal size orbit each other, and triple asteroid systems are known as well. Many asteroids seemingly have been captured by a planet’s gravity and become moons — likely candidates include Mars’ moons, Phobos and Deimos, and most of the outer moons of Jupiter, Saturn, Uranus and Neptune.

The average temperature of the surface of a typical asteroid is minus 100 degrees Fahrenheit (minus 73 degrees Celsius). Asteroids have stayed mostly unchanged for billions of years — as such, research into them could reveal a great deal about the early solar system.

Asteroids come in a variety of shapes and sizes. Some are solid bodies, while others are smaller piles of rubble bound together by gravity. One, which orbits the sun between Neptune and Uranus, comes with its own set of rings. Another has not one but six tails.

Classification

Asteroids lie within three regions of the solar system. Most asteroids lie in a vast ring between the orbits of Mars and Jupiter. This main asteroid belt holds more than 200 asteroids larger than 60 miles (100 km) in diameter. Scientists estimate the asteroid belt also contains between 1.1 million and 1.9 million asteroids larger than 1 km (3,281 feet) in diameter and millions of smaller ones.

Not everything in the main belt is an asteroid — Ceres, once thought of only as an asteroid, is now also considered a dwarf planet. In the past decade, scientists have also identified a class of objects known as “main belt asteroids,” small rocky objects with tails. While some of the tails form when objects crash into an asteroid, or by disintegrating asteroids, others may be comets in disguise.

Many asteroids lie outside the main belt. Trojan asteroids orbit a larger planet in two special places, known as Lagrange points, where the gravitational pull of the sun and the planet are balanced. Jupiter Trojans are the most numerous, boasting nearly as high a population as the main asteroid belt. Neptune, Mars and Earth also have Trojan asteroids.

Near-Earth asteroids (NEAs) circle closer to Earth than the sun. Amor asteroids have close orbits that approach but no not cross Earth’s path, according to NASA. Apollo asteroids have Earth-crossing orbits but spend most of their time outside the planet’s path. Aten asteroids also cross Earth’s orbit but spend most of their time inside Earth’s orbit. Atira asteroids are near-Earth asteroids whose orbits are contained within Earth’s orbit. According to the European Space Agency, roughly 10,000 of the known asteroids are NEAs.

In addition to classifications of asteroids based on their orbits, most asteroids fall into three classes based on composition:

The C-type or carbonaceous asteroids are grayish in color and are the most common, including more than 75 percent of known asteroids. They probably consist of clay and stony silicate rocks, and inhabit the main belt’s outer regions.

The S-type or silicaceous asteroids are greenish to reddish in color, account for about 17 percent of known asteroids, and dominate the inner asteroid belt. They appear to be made of silicate materials and nickel-iron.

The M-type or metallic asteroids are reddish in color, make up most of the rest of the asteroids, and dwell in the middle region of the main belt. They seem to be made up of nickle-iron.

There are many other rare types based on composition as well — for instance, V-type asteroids typified by Vesta have a basaltic, volcanic crust.

Earth impacts

Ever since Earth formed about 4.5 billion years ago, asteroids and comets have routinely slammed into the planet. The most dangerous asteroids are extremely rare, according to NASA.

An asteroid capable of global disaster would have to be more than a quarter-mile wide. Researchers have estimated that such an impact would raise enough dust into the atmosphere to effectively create a “nuclear winter,” severely disrupting agriculture around the world. Asteroids that large strike Earth only once every 1,000 centuries on average, NASA officials say.

Smaller asteroids that are believed to strike Earth every 1,000 to 10,000 years could destroy a city or cause devastating tsunamis. According to NASA, space rocks smaller than 82 feet (25 m) will most likely burn up as they enter Earth’s atmosphere, which means that even if 2015 TC25 hit Earth, it probably wouldn’t make it to the ground.

On Feb. 15, 2013, an asteroid slammed into the atmosphere over the Russian city of Chelyabinsk, creating a shock wave that injured 1,200 people. The space rock is thought to have measured about 65 feet (20 m) wide when it entered Earth’s atmosphere.

When an asteroid, or a part of it, crashes into Earth, it’s called a meteorite. Here are typical compositions:

Iron meteorites

  • Iron: 91 percent
  • Nickel: 8.5 percent
  • Cobalt: 0.6 percent

Stony meteorites

  • Oxygen: 6 percent
  • Iron: 26 percent
  • Silicon: 18 percent
  • Magnesium: 14 percent
  • Aluminum: 1.5 percent
  • Nickel: 1.4 percent
  • Calcium: 1.3 percent

Asteroid defense

Dozens of asteroids have been classified as “potentially hazardous” by the scientists who track them. Some of these, whose orbits come close enough to Earth, could potentially be perturbed in the distant future and sent on a collision course with our planet. Scientists point out that if an asteroid is found to be on a collision course with Earth 30 or 40 years down the road, there is time to react. Though the technology would have to be developed, possibilities include exploding the object or diverting it.

For every known asteroid, however, there are many that have not been spotted, and shorter reaction times could prove more threatening.

When asteroids do close flybys of Earth, one of the most effective ways to observe them is by using radar, such as the system at NASA’s Goldstone Deep Space Communications Complex in California. In September 2017, the near-Earth asteroid 3122 Florence cruised by Earth at 4.4 million miles (7 million km), or 18 times the distance to the moon. The flyby confirmed its size (2.8 miles or 4.5 km) and rotation period (2.4 hours). Radar also revealed new information such as its shape, the presence of at least one big crater, and two moons.

In a NASA broadcast from earlier in 2017, Marina Brozovic, a physicist at NASA’s Jet Propulsion Laboratory, said radar can reveal details such as its size, its shape, and whether the asteroid is actually two objects (a binary system, where a smaller object orbits a larger object.) “Radar is a little bit like a Swiss army knife,” she said. “It reveals so much about asteroids all at once.”

In the unlikely event that the asteroid is deemed a threat, NASA has a Planetary Defense Coordination Office that has scenarios for defusing the situation. In the same broadcast, PDCO planetary defense officer Lindley Johnson said the agency has two technologies at the least that could be used: a kinetic impactor (meaning, a spacecraft that slams into the asteroid to move its orbit) or a gravity tractor (meaning, a spacecraft that remains near an asteroid for a long period of time, using its own gravity to gradually alter the asteroid’s path.) PDCO would also consult with the White House and the Federal Emergency Management Agency (FEMA) and likely other space agencies, to determine what to do. However, there is no known asteroid (or comet) threat to Earth and NASA carefully tracks all known objects through a network of partner telescopes.

Water delivery?

Ironically, the collisions that could mean death for humans may be the reason we are alive today. When Earth formed, it was dry and barren. Asteroid and comet collisions may have delivered the water-ice and other carbon-based molecules to the planet that allowed life to evolve. At the same time, the frequent collisions kept life from surviving until the solar system calmed down. Later collisions shaped which species evolved and which were wiped out.

According to NASA’s Center for Near Earth Object Studies CNEOS), “It seems possible that the origin of life on the Earth’s surface could have been first prevented by an enormous flux of impacting comets and asteroids, then a much less intense rain of comets may have deposited the very materials that allowed life to form some 3.5 – 3.8 billion years ago.”

Discovery & naming

In 1801, while making a star map, Italian priest and astronomer Giuseppe Piazzi accidentally discovered the first and largest asteroid, Ceres, orbiting between Mars and Jupiter. Although Ceres is classified today as a dwarf planet, it accounts for a quarter of all the mass of all the known asteroids in or near the main asteroid belt.

Over the first half of the 19th century, several asteroids were discovered and classified as planets. William Herschel coined the phrase “asteroid” in 1802, but other scientists referred to the newfound objects as minor planets. By 1851, there were 15 new asteroids, and the naming process shifted to include numbers, with Ceres being designated as (1) Ceres. Today, Ceres shares dual designation as both an asteroid and a dwarf planet, while the rest remain asteroids.

Since the International Astronomical Union is less strict on how asteroids are named when compared to other bodies, there are asteroids named after Mr. Spock of “Star Trek” and rock musician Frank Zappa, as well as more solemn tributes, such as the seven asteroids named for the crew of the Space Shuttle Columbia killed in 2003. Naming asteroids after pets is no longer allowed.

Asteroids are also given numbers — for example, 99942 Apophis.

Exploration

The first spacecraft to take close-up images of asteroids was NASA’s Galileo in 1991, which also discovered the first moon to orbit an asteroid in 1994.

In 2001, after NASA’s NEAR spacecraft intensely studied the near-earth asteroid Eros for more than a year from orbit, mission controllers decided to try and land the spacecraft. Although it wasn’t designed for landing, NEAR successfully touched down, setting the record as the first to successfully land on an asteroid.

In 2006, Japan’s Hayabusa became the first spacecraft to land on and take off from an asteroid. It returned to Earth in June 2010, and the samples it recovered are currently under study.

NASA’s Dawn mission, launched in 2007, began exploring Vesta in 2011. After a year, it left the asteroid for a trip to Ceres, arriving in 2015. Dawn was the first spacecraft to visit Vesta and Ceres. As of 2017, the spacecraft still orbits the extraordinary asteroid.

In September 2016, NASA launched the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx), which will explore the asteroid Bennu before grabbing a sample to return to Earth.

“Sample return is really at the forefront of scientific exploration,” OSIRIS-REx principal investigator Dante Lauretta said at a press conference.

In January 2017, NASA selected two projects, Lucy and Psyche, via its Discovery Program. Planned to launch in October 2021, Lucy will visit an object in the asteroid belt before going on to study six Trojan asteroids. Psyche will travel to 16 Psyche, an enormous metallic asteroid that may be the core of an ancient Mars-size planet, stripped of its crust through violent collisions.

In 2012, a company called Planetary Resources, Inc. announced plans to eventually send a mission to a space rock to extract water and mine the asteroid for precious metals. Since then, NASA has begun to work on plans for its own asteroid-capture mission.

According to CNEOS, “It has been estimated that the mineral wealth resident in the belt of asteroids between the orbits of Mars and Jupiter would be equivalent to about 100 billion dollars for every person on Earth today.”

 

The Hypersonic Synergetic Rocket Engine – Sabre – is designed to drive space planes to orbit

Hypersonic jet travel across the Atlantic has moved a step closer after scientists successfully tested technology to stop jet engines melting at speeds up to 25 times the speed of sound.

Researchers at Reaction Engines managed to make a ‘pre cooler’ work at a simulated speed of 3.3 mach or 2,500 mph (4,023kph) – that means large scale hypersonic engines that could be fitted to passenger jets are a step closer to being realised.

Their experimental Synergetic Air Breathing Rocket Engine (Sabre) is designed to be fitted to large aircraft to ferry passengers around the world in hours and deliver goods into orbit for less.

The ‘pre-cooler’, which lets the aircraft travel at high speed without hot air rushing in and causing the engine to melt was tested at simulated speeds of more than three times the speed of sound. The next stage of tests will see the technology tested at Mach 5.5 (4,200mph / 6,800kph), and could one day lead to flights between London and New York that take less than an hour. 

UK engineers have completed a milestone test of their new high-speed 'spaceplane' which they say could be able to fly at 25 times the speed of sound (mach 25). Reaction Engines has tested a 'pre-cooler' technology - which allows aircraft to travel faster than ever

UK engineers have completed a milestone test of their new high-speed ‘spaceplane’ which they say could be able to fly at 25 times the speed of sound (mach 25). Reaction Engines has tested a ‘pre-cooler’ technology – which allows aircraft to travel faster than ever

Reaction built a testing facility on the ground in Colorado and used a General Electric J79 turbojet engine to replicate the conditions that the vehicle will experience at hypersonic speeds.

The firm hopes to make a reusable vehicle that would combine the fuel efficiency of a jet engine with the power and speed of a rocket.

Reaction, based in Oxfordshire, believe that the aircraft could travel the distance between New York and London in less than an hour when running at it’s proposed top speed.

The company also wants to take people and payloads into space and return to Earth.

A spokesperson for Reaction Engines told MailOnline that although this technology is decades away from use in passenger jets, the technology could be used in more immediate applications.

The heat exchanger technology has a wide range of potential commercial applications and the ability to revolutionise the approach to thermal management across a range of industries; from aerospace to motorsport, industrial processes, and the oil and gas industry.

The heat exchanger technology has a wide range of potential commercial applications and the ability to revolutionise the approach to thermal management across a range of industries; from aerospace to motorsport, industrial processes, and the oil and gas industry

The heat exchanger technology has a wide range of potential commercial applications and the ability to revolutionise the approach to thermal management across a range of industries; from aerospace to motorsport, industrial processes, and the oil and gas industry

The breakthrough test was conducted at the company’s newly opened TF2 test facility at Colorado Air and Space Port.

It comes 30 years after Reaction Engines was formed in the UK around an engine cycle concept to enable access to space and hypersonic air-breathing flight from a standing start.

The pre-cooling technology is designed to lower the temperature of the air coming into the engine from more than 1,000°C (1,832°F) to room temperature in one twentieth of a second.

To do this, the team developed a heat-exchanger to manage very high temperature airflows.

Reaction Engines has tested a 'pre-cooler' technology - which allows aircraft to travel faster than ever. The experimental Synergetic Air Breathing Rocket Engine - Sabre - is designed to drive space planes to orbit and take airliners around the world in just a few hours

Reaction Engines has tested a ‘pre-cooler’ technology – which allows aircraft to travel faster than ever. The experimental Synergetic Air Breathing Rocket Engine – Sabre – is designed to drive space planes to orbit and take airliners around the world in just a few hours

The tech is designed to chill air in the inlet of high-speed turbojets for hypersonic vehicles and ultimately will form the basis for the company’s Sabre engine for low-cost repeatable access to space.

The goal is to incorporate this technology into their Sabre engine, which would work like an ‘air breathing rocket engine’.

It would carry significantly less fuel oxidant than a conventional rocket, making it much lighter.

From take-off to Mach 5.5 (5.5 times the speed of sound), it would take oxygen from the atmosphere, which would be fed into a rocket combustion chamber.

During tests, at simulated speeds of Mach 3.3, or more than three times the speed of sound. To replicate the conditions that it will experience at hypersonic speeds, Reaction built a testing facility on the ground in Colorado and used a General Electric J79 turbojet engine

During tests, at simulated speeds of Mach 3.3, or more than three times the speed of sound. To replicate the conditions that it will experience at hypersonic speeds, Reaction built a testing facility on the ground in Colorado and used a General Electric J79 turbojet engine

The tech is designed to chill air in the inlet of high-speed turbojets for hypersonic vehicles and ultimately will form the basis for the company’s Sabre engine for low-cost repeatable access to space. The goal is to incorporate this technology into their Sabre engine, which would work like an 'air breathing rocket engine'

The tech is designed to chill air in the inlet of high-speed turbojets for hypersonic vehicles and ultimately will form the basis for the company’s Sabre engine for low-cost repeatable access to space. The goal is to incorporate this technology into their Sabre engine, which would work like an ‘air breathing rocket engine’

Here, it would be ignited along with stored liquid hydrogen and then switch at high altitude, burning liquid oxygen and liquid hydrogen from on-board fuel tanks.

Mark Thomas, the Reaction Engines chief executive, told the Times: ‘If you can pull it off, it’s a game changer. It kicks conventional rocket engines into touch.’

It did this by successfully quenching a 420°C (788°F) stream of gases in less than 1/20th of a second.

At low altitude and low speeds, it would behave like a jet, burning its fuel in a stream of air scooped from the atmosphere.

At high speeds and at high altitude, it would transition to full rocket mode, combining the fuel with the oxygen carried inside.

They envisage that it would be able aircraft that could travel the distance between New York and London in less than an hour. They also want to take people or payloads into space and return to Earth

They envisage that it would be able aircraft that could travel the distance between New York and London in less than an hour. They also want to take people or payloads into space and return to Earth

HOW DOES REACTION ENGINES’ ‘SABRE’ ENGINE WORK?

Reaction Engines Limited (REL), based at Culham in Oxfordshire, is working on a turbine that combines both jet and rocket technologies. 

The Sabre engine works by burning atmospheric air in combustion chambers.

It then uses the heat to turbo-charge the engine.

The Sabre engine works by burning atmospheric air in combustion chambers. It then uses the heat to turbo-charge the engine

The Sabre engine (artist’s impression) works by burning atmospheric air in combustion chambers. It then uses the heat to turbo-charge the engine

At the moment, rockets have to carry liquid oxygen and liquid hydrogen to power them and the cost of carrying this heavy fuel is expensive. 

The new engine creates its own liquid oxygen by cooling air entering the engine from 1,000°C to minus 150°C in a hundredth of a second – six times faster than the blink of an eye – without creating ice blockages.

This new class of aerospace engine is designed to enable aircraft to operate from standstill on the runway to speeds of over five times the speed of sound in the atmosphere.

It can then transition to a rocket flight mode, allowing spaceflight at speeds up to orbital velocity, equivalent to 25 times the speed of sound.