Latest News on Apophis: 13 -year-old Boy Corrects NASA’s Estimates of Earth Impact — Not! (Update)

Annimation of Apophis.  Image Credit:  Osservatorio Astronomico Sormano
Update: It turns out this story is a fabrication and AFP didn’t check the facts with NASA as I suspected. According to the blog Cosmos4u, they talked with Don Yeomans at NASA’s NEO office and this is what Yeoman’s said about the news story of a 13-year old boy correcting NASA’s estimates of Apohpis impacting earth: “We have not corresponded with this young man and this story is absurd, a hoax or both. During its 2029 Earth close approach, Apophis will approach the Earth to about 38,900 km, well inside the geosynchronous distance at 42,240 km. However, the asteroid will cross the equatorial belt at a distance of 51,000 km – well outside the geosynchronous distance. Since the uncertainty on Apophis’ position during the Earth close approach is about 1500 km, Apophis cannot approach an Earth satellite. Apophis will not cross the moon’s orbital plane at the Moon’s orbital distance so it cannot approach the moon either.”

Also, the scientist mentioned in AFP’s story said he wasn’t conferred with either by the news agency. So don’t give any heed to this story that has been running amok around the internet.

But here’s our story on this as it originally ran: Here’s a story that supports the value of science fairs. And it also makes one wonder where else NASA’s decimal points might be off by a couple of places. One caveat on this news piece, however: as far as I know there hasn’t been an official NASA press release on this.

Reportedly, a 13-year-old German schoolboy doing research for a science competition found errors in NASA’s estimates on the chances of the asteroid Apophis colliding with Earth. The boy, Nico Marquardt used data from the Institute of Astrophysics in Potsdam to calculate that there was a 1 in 450 chance that the Apophis asteroid will collide with Earth. NASA had previously estimated the chances at only 1 in 45,000, but according to an AFP news release, NASA now acknowledges the kid is right. (Actually, no they don’t.)
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Ancient Asteroids Discovered

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Way back in the beginning of the solar system, about 4.5 billion years ago, the first materials began to condense from gasses into solid particles. These materials were rich in calcium and aluminum. Astronomers have thought that at least some of the solar system’s oldest asteroids should have plenty of these two elements, but no asteroids had ever been found that were particularly rich in them. Until now. A team of scientists recently identified three previously unknown asteroids that appear to be among the oldest objects in our solar system.

Using visible and infrared data from telescopes on Mauna Kea in Hawaii, astronomers from the University of Maryland found asteroids that appear to relatively unchanged since they formed in the early stages of our solar system’s development. “We have identified asteroids that are not represented in our meteorite collection and which date from the earliest periods of the Solar System,” said research astronomer Jessica Sunshine. “These asteroids are prime candidates for future space missions that could collect and return samples to Earth, providing a more detailed understanding of the Solar System’s first few millions of years.”

Meteorites found on Earth do contain small amounts of calcium and aluminum. Called calcium aluminum inclusions (CAIs) these white, millimeter-sized objects are found in meteorites, often together with chondrules, which are small balls of iron or magnesium.

In 2002, an international team of scientists accurately dated CAIs at 4.57 billion years, making them the oldest known objects in the solar system. When the famous Allende meteorite was found in 1969, scientists first recognized these inclusions matched many properties expected to be found in the early solar system.

Sunshine’s team used the SpeX instrument at the NASA Infrared Telescope facility to look at the surface of asteroids, looking for “fingerprints” indicative of CAIs. Sunshine said that several asteroids have been found that contain 2-3 times more CAI materials than any known meteorite. “It appears ancient asteroids have indeed survived, and we know where they are,” she said.

Original news source: Eureka Alert

Life Thrived After More Than 100 Meteorites Struck the Earth

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Yesterday we talked about the discovery of amino acids in meteorites. And then today comes news that there was an explosion of life (pardon the pun) after meteorites rained down more than 400 million years ago. Even though the Earth was struck by more than 100 1-km meteorites in a short period of time, life not only survived, it thrived.

The string of impacts occurred during the Ordovician period, between 490-440 million years ago. It wasn’t quite life as we know it, but creatures were living on land, and organisms had evolved to fit every niche in the oceans.

According to planetary scientists, a disruption in the asteroid belt about 470 million years ago sent hundreds of space rocks out of their normal orbit, and into ours.

Over a few million years, more than 100 separate meteorites larger than 1 km across struck the Earth, throwing up a Sun-clogging shroud of dust. Plants, starved for sunlight, died, and the chains of life depending on them collapsed.

But incredibly, life thrived after this period, evolving into new and interesting life forms.

Researchers from the University of Copenhagen and Lund University gathered together chemical samples from meteorites, fossils, and examined several craters in Sweden. The Lockne crater, for example, is located in northern Sweden and has a diameter of 7.5 km across.

They found evidence for the thriving life forms in layers newer than the ones containing debris from the meteorite strikes.

“You could say that biological evolution experienced a serious boost within a relatively short period of time. And, as is the case with, for example, volcanic eruptions or large forest fires, the impacts initially had a devastating effect on all life, but from the ashes arose a much richer fauna than had existed previously,” said Dave Harper from the University of Copenhagen.

This is research we’ve seen before. Paleontologists announced earlier this year that life can bounce back quickly from an extinction event, but it takes a long time for the true diversity of life to reappear. So, after most life is wiped out by an asteroid, the cockroaches and rats take over. You might have the same number of creatures, but it takes many years before you get rich ecosystems with butterflies and giraffes too.

Original Source: Nature Geoscience

Earth Life Forms Ejected on Asteroid Impact Could Survive and Return Again

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Does this mean that, perhaps, we can go home again?

If an asteroid or comet impacted Earth, the resulting ejection of materials could contain life forms. According to a study published in the journal Astrobiology, these life forms could survive and then seed another planet or moon with life. Additionally, Earth could also be re-seeded with life by those same life forms.

Ah, there’s no place like home.

If rock fragments containing embedded microorganisms were ejected into space, at least some of those organisms might survive and reseed Earth or seed another planetary surface able to support life. This scenario, which is called lithopanspermia was examined in studies called systematic shock recovery experiments designed to simulate this type of situation where microorganisms are transported between planets via meteorites.

The researchers sandwiched dry layers of three kinds of biological test ingredients, including bacterial endospores, endolithic cyanobacteria, and epilithic lichens, into rocks analogous to rocks from Mars. They then simulated the shock pressures Martian meteorites experienced when they were ejected from Mars and determined the ability of the organisms to survive the harsh conditions.

The organisms are hardy examples of microbes that can withstand extreme environmental stress and represent potential ‘hitchhikers’ within impact-ejected rocks.

“Given that impacts have occurred on planetary bodies throughout the history of our solar system,” says Sherry L. Cady, PhD, Associate Professor in the Department of Geology at Portland State University, “the hypothesis that life in rock could have been transferred between planets at different times during the past 3.5 billion years is plausible.”

And not only is it plausible that Mars rocks could be transferred to Earth and vice versa, but ejected rocks from Earth could possibly return and land back on their home planet. Given the contemplation of the destruction of life on Earth, it’s somewhat comforting to think that we could perhaps start over again from our own ingredients.

Original News Source: Astrobiology Press Release

“Foresight” Wins First Prize in Apophis Asteroid Tagging Competition

The Near Earth Asteroid (NEO) Apophis is expected to flyby the Earth in 2029. However, this flyby will be more of a “fly-very-close” as the lump of rock will miss the Earth by only a few thousand kilometers. This near-miss isn’t worrying scientists too much, but should the asteroid tumble through a 400 meter gravitational “keyhole”, there is concern that the asteroid could swing by and risk another collision in 2036. Although the odds are fairly slim, astronomers need better precision in calculating Apopis’s orbital trajectory.

How can this be done? Why not send a spaceship to shadow the asteroid on its journey? The Planetary Society has announced just that. The winning design of the Apophis Mission Design Competition will send a probe and tag Apophis to gain more details about this interplanetary vagabond, and has been awarded a healthy $25,000 to help the development of the US “Foresight” mission…

99942 Apophis (otherwise known as asteroid 2004 MN4) caused quite a stir back in 2004 when it was discovered. Lacking detailed observation at the time, the probability of the 270 meter long piece of rock hitting the Earth was around 2.7% – a large risk in astronomical terms. Now we are sure the asteroid will fly straight by, albeit rather close. It is estimated that Apophis will pass within the orbit of geostationary satellites located at 35,786 km above Earth, allowing amateur astronomers a great opportunity to observe the NEO (it will be possible to see the asteroid with the naked eye at night), whilst being secure in the knowledge that it’s not going to come any closer.

So, panic over? Not quite. Although Apophis will miss us on its first approach in 2029, we might not be so lucky on one of its return trips in 2036. During its flyby in 2029, should the asteroid pass through a critical gravitational “keyhole” measuring only 400 meters across, the gravitational deflection applied to the Apophis asteroid may adjust its orbit, setting it up for a collision course with Earth seven years later.

This is the reason for events such as the Planetary Society’s Apophis Mission Design Competition, to raise awareness of the risk posed by NEOs. Although the winning entry, designed by SpaceWorks Engineering Inc. (Atlanta, Georgia) in conjunction with SpaceDev Inc. (Poway, California), is in the design phase, it is hoped that the completed project could launch by 2012. “Foresight” is intended to fly to Apophis and tag the rock with tracking equipment. The orbiter will continue to study the asteroid and follow it on its orbit around the Sun, gathering valuable information about its composition, center of mass, surface features and, most importantly, its trajectory.

Missions plans such as Foresight are required by the international community to be used should the threat of an asteroid collision become reality (and not remain in cheesy sci-fi movies like Deep Impact or Armageddon).

Apophis isn’t science fiction, it isn’t a blockbuster Hollywood movie; it is very real.” – Dan Geraci, the Planetary Society’s board chairman.

For more information on the winning entry and the other award winning designs, see the Planetary Society’s Apophis Mission Design Competition website.

Could Primordial Black Holes Deflect Asteriods on a Collision Course with Earth?

An artists impression of an asteroid belt. Credit: NASA

Primordial black holes (PBHs) are getting mischievous again. These artefacts from the Big Bang could be responsible for hiding inside planets or stars, they may even punch a neat, radioactive hole through the Earth. Now, they might start playing interplanetary billiards with asteroids in our solar system.

Knocking around lumps of rock may not sound very threatening when compared with the small black holes’ other accolades, but what if a large asteroid was knocked off course and sent in our direction? This could be one of the most catastrophic events yet to come from a PBH passing through our cosmic neighborhood…

As a race, we are constantly worried about the threat of asteroids hitting Earth. What if another large asteroid – like the one that possibly killed the dinosaurs around 65 million BC or the one that blew up over Tunguska in 1908 – were to come hurtling through space and smash into the Earth? The damage caused by such an impact could devastate whole nations, or plunge the world as we know it to the brink of extinction.

But help is at hand. From the combined efforts by groups such as NASAs Near Earth Object Program and international initiatives, governments and institutions are beginning to take this threat seriously. Tracking threatening Near Earth Asteroids is a science in itself, and for now at least, we can relax. There are no massive lumps of rock coming our way (that we know of). The last scare was a comparatively small asteroid called “2008 CT1” which came within 135,000 km of the Earth (about a third of the distance to the Moon) on February 5th, but there are no others forecast for some time.

So, we now have NEO monitoring down to a fine art – we are able to track and calculate the trajectory of observed asteroids throughout the solar system to a very high degree of accuracy. But what would happen if an asteroid should suddenly change direction? This shouldn’t happen right? Think again.

A researcher from the Astro Space Center of the P. N. Lebedev Physics Institute in Moscow has published works focusing on the possibility of asteroids veering off course. And the cause? Primordial black holes. There seems to be many publications out there at the moment musing what would happen should these black holes exist. If they do exist (and there is a high theoretical possibility that they do), there’s likely to be lots of them. So Alexander Shatskiy has gotten to the task of working out the probability of a PBH passing through the solar systems asteroid belts, possibly kicking an asteroid or two across Earths orbit.

Shatskiy finds that PBHs of certain masses are able to significantly change an asteroids orbit. There are estimates of just how big these PBHs can be, the lower limit is set by black hole radiation parameters (as theorized by Stephen Hawking), having little gravitational effect, and the upper limit is estimated to be as massive as the Earth (with an event horizon radius of an inch or so – golf ball size!). Naturally, the gravitational influence by the latter will be massive, greatly affecting any piece of rock as it passes by.
Real-time map of the distribution of thousands of known asteroids around the inner solar system. Red and yellow dots represent high risk NEOs (credit: Armagh Observatory)
Should PBHs exist, the probability of finding one passing though the solar system will actually be quite high. But what is the probability of the PBH gravitationally scattering asteroids as it passes? If one assumes a PBH with a mass corresponding to the upper mass estimate (i.e. the mass of the Earth), the effect of local space would be huge. As can be seen from an asteroid map (pictured), there is a lot of rocky debris out there! So something with the mass of the Earth barrelling through and scattering an asteroid belt could have severe consequences for planets nearby.

Although this research seems pretty far-fetched, one of the calculations estimate the average periodicity of a large gravitationally disturbed asteroids falling to Earth should occur every 190 million years. According to geological studies, this estimate is approximately the same.

Shatskiy concludes that should small black holes cause deflection of asteroid orbits, perhaps our method of tracking asteroids may be outdated:

If the hypothesis analyzed in this paper is correct, modern methods aimed at averting the asteroid danger appear to be inefficient. This is related to the fact that their main idea is revealing big meteors and asteroids with dangerous orbits and, then, monitoring these bodies. However, if the main danger consists in abrupt changes of asteroidal orbits (because of scattering on a PBH), revealing potentially dangerous bodies is hardly possible.”

Oh dear, we might be doomed after all…

Source: arXiv

An Elegant Proposal for Near Earth Asteroid Deflection

Image Credit: NASA

Although the chances of an asteroid hitting Earth appear to be small for any given year, the consequences of such an event would be monumental. The science community has come up with some ideas and proposals for ways to mitigate the threat of an incoming asteroid hitting the Earth. Some proposals suggest almost Hollywood type theatrics of launching nuclear weapons to destroy the asteroid, or slamming a spacecraft into a Near Earth Object to blow it apart. But other ideas employ more simple and elegant propositions to merely alter the trajectory of the space rock. One such plan uses a two-piece solar sail called a solar photon thruster that draws on solar energy and resources from the asteroid itself.

Physicist Gregory Matloff has been working with NASA’s Marshall Spaceflight Center to study the two-sail solar photon thruster which uses concentrated solar energy. One of the sails, a large parabolic collector sail would constantly face the sun and direct reflected sunlight onto a smaller, moveable second thruster sail that would beam concentrated sunlight against the surface of an asteroid. In theory, the beam would vaporize an area on the surface to create a ‘jet’ of materials that would serve as a propulsion system to alter the trajectory of the Near Earth Object (NEO.)

Changing the trajectory of a NEO exploits the fact that both the Earth and the impactor are in orbit. An impact occurs when both reach the same point in space at the same time. Since the Earth is approximately 12,750 km in diameter and moves at about 30 km per second in its orbit, it travels a distance of one planetary diameter in about seven minutes. The course of the object would be altered, or either delayed or advanced and cause it to miss the Earth.

But of course, the arrival time of the impactor must be known very accurately in order to forecast the impact at all, and to determine how to affect its velocity.

Additionally, the solar photon thruster’s performance would vary depending on the unique makeup of each NEO. For example, asteroids with a greater density, radius or rate of rotation would cause decreased performance of the solar photon thruster in acceleration and deflection.

Even though the solar photon thruster appears to be efficient in its performance, Matloff said that more than half of the solar energy delivered to the “hotspot” on the NEO would not be available to vaporize and accelerate the jet due to other thermodynamic processes such as conduction, convection, and radiation. As expected, a larger collector sail radius would increase the amount of energy available, and would increase acceleration of the NEO. Matloff said this system allows the sail craft to “tack” against the solar-photon breeze at a larger angle than conventional single solar sails can achieve.

This system of sails would not be attached to the NEO, but would be kept nearby the NEO “on station” either with its own thrusting capability or by auxiliary electric propulsion. More studies would be needed to ascertain if a supplementary propulsion system would be necessary.

The sails used in the study were both inflatable. However, Matloff believes it might be worth considering a small rigid thruster sail, which might simplify deployment and reduce occultation.

Said Matloff, “Hopefully, future design studies will resolve these uncertainties before application of NEO-diversion technology becomes necessary.”

Arecibo Spots a Triple Asteroid

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Since asteroids have mass, they have gravity. And if you’ve got gravity, you can have moons. Several asteroids have been discovered in the outer Solar System with smaller asteroidlets circling them. But now the Arecibo radio telescope in Puerto Rico has turned up the closest example – a triple system just a mere 11 million km (7 million miles) from Earth.

Asteroid 2001 SN263 was revealed to be a triple system by Cornell astronomer Michael C. Nolan. The asteroid itself had been discovered back in 2001 as part of an automated survey. He and his colleagues captured radio images of the space rocks on February 11. By studying the images, they realized that they actually had a system of three objects.

The main central asteroid is roughly 2 km (1.5 miles) across. The larger “moon” is about half that size, and the smallest is about 300 metres (1,000 feet) across.

Asteroid systems like this have been seen in the Asteroid Belt, between Mars and Jupiter, but never so close. This allows scientists to image it with unprecedented detail.

As researchers find more and more near-Earth asteroids, they’re starting to realize that binary systems are actually quite common. According to Nolan, one in six near-Earth asteroids is a binary. Although, this is the first near-Earth triple system seen.

Multiple asteroid systems are very useful for astronomers; they provide the mass calculation. In a multiple object system like this, you can calculate the mass of each object by knowing the various periods (the time they take to complete an orbit). Researchers can then compare the mass of the binary objects to the brightness of single asteroids to estimate their masses as well.

One of the big unanswered questions: did the three objects form together, or were they captured later on? By watching the system over time, Nolan and his team will get a better sense if they’re orbiting on the exact same plane (like our Solar System). This will be evidence they formed together billions of years ago.

Arecibo is one of the best asteroid hunting tools available to astronomers; unfortunately, budget cuts in the United States has put the future of the facility in jeopardy.

Original Source: Cornell News Release

Another Asteroid Passes Close to Earth

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On Tuesday, February 5, 2008 an SUV sized asteroid passed between the Earth and the moon. Asteroid 2008 CT1 came within 135,000 kilometers ( 84,000 miles) of Earth, only a third of the distance to the moon. The asteroid was discovered only two days before its close approach to Earth, spotted by the Lincoln Near Earth Asteroid Research (LINEAR) project, using robotic telescopes located at New Mexico’s White Sands Missile Range. The asteroid’s size is estimated between 8 – 15 meters.

While this asteroid seems small, we know that even small rocks can be devastating. Last September, a meteorite estimated at .2 – 2 meters wide created a crater 13 meters wide in Peru. The cause of the Tunguska Event of the early 20th Century is now believed to be a 35m rock that never even touched the ground. It’s believed that it exploded a few miles above the ground, creating a shockwave that devastated the landscape below.

2008 CT1 could possibly return to Earth’s vicinity in 2041, although its orbit has not yet been well defined, so that prediction could change. It is also a possible Mercury impactor, since that that planet is very near the asteroid’s currently calculated perihelion.

LINEAR uses a Ground-based Electro-Optical Deep Space Surveillance (GEODSS) telescope, and has detected over 3,000,000 asteroids since 1998, which is about 70% of the known near-Earth asteroids.

The GEODSS Telescope.  Image Credit:  LINEAR

Original News Source: SLOOH Skylog

Alarmist Asteroid 2007 TU24 Video

At the time I’m writing this, asteroid 2007 TU24 has nearly passed the Earth. As we’ve been hammering on here on Universe Today, the Earth is completely safe. Only if you have a telescope and know exactly where to look, will you stand a chance of spotting the flyby.

Even though he posted a video last week, debunking the collision claims, Bad Astronomer and (former) friend Phil Plait seems to have recanted.

Lowest form of life? Ouch.

Thanks to IronmanAustralia for the laugh. I’m still wiping the tears out of my eyes.

On another note, this is the first time I’ve tried embedding a YouTube video in Universe Today. I’m sure I’ve messed it up somehow. Let me know if you like this, and want more.