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Chasing ‘Oumuamua—unfortunately human technology isn’t up to the task

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This article was written by Eric Berger for Ars Technica. Click here to continue reading the article on ArsTechnica.com

A little more than a month ago, an interstellar visitor now known as ‘Oumuamua passed within 24 million kilometers of Earth. It is now moving rapidly away from the Sun at a velocity of approximately 26km/s. That is considerably faster than, say, the Voyager 1 spacecraft, which is hurtling beyond the Solar System at a velocity of 17km/s.

The first interstellar object is doubly intriguing because humans have never been able to study something from beyond the Solar System up close. Moreover, recent observations have shown that ‘Oumuamua has a reddish color, astronomers say, and unexpected oblong shape, like that of a giant, 400-meter-long cigar. Already, the object is fading from view, and we will never see it again as it zooms away.

But what if we could? NASA is building what will be the world’s most powerful rocket, the Space Launch System. Would it be capable of launching a small probe to catch ‘Oumuamua? Do we have any technology that can catch this interstellar interloper?

Catch me if you can

To find out, Ars turned to the Advance Concepts Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The office’s manager, Mark Rogers, spoke to Ars, as did one of his mission planners, Larry Kos. It turns out they were curious, too, and had done some preliminary calculations on the possibility of intercepting ‘Oumuamua.

The short answer is, unfortunately, we are too late now with our existing technology. Although ‘Oumuamua is moving at a velocity of 26km/s, factoring in Earth’s velocity vector, the delta-v between a spacecraft in Earth orbit and the object is closer to 60km/s. “Chemical propulsion just doesn’t close the case in this scenario,” Rogers said. “It’s not feasible.”

But what if NASA had worked feverishly after detection of the object on October 19 and already sent a probe into space? The problem with our primary propulsion methods is that, while chemical rockets are very good at getting stuff out of Earth’s orbit, they’re gas guzzlers in space. Most of our existing in-space propulsion systems are based on chemicals, and they need a lot of fuel—often hydrogen—to move a spacecraft about. In this case, Kos calculated the specific impulse needed for chemical rocket engines to catch ‘Oumuamua at about 450 seconds.

Continue reading (via ArsTechnica.com)

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Solar System’s First Interstellar Visitor Dazzles Scientists

Artist’s impression of the interstellar asteroid `Oumuamua

This article was originally published by NASA. You can continue reading it on the NASA website, here.

Now, new data reveal the interstellar interloper to be a rocky, cigar-shaped object with a somewhat reddish hue. The asteroid, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date. While its elongated shape is quite surprising, and unlike asteroids seen in our solar system, it may provide new clues into how other solar systems formed.

The observations and analyses were funded in part by NASA and appear in the Nov. 20 issue of the journal Nature. They suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.

“For decades we’ve theorized that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “This history-making discovery is opening a new window to study formation of solar systems beyond our own.”

Immediately after its discovery, telescopes around the world, including ESO’s Very Large Telescope in Chile and other observatories around the world were called into action to measure the object’s orbit, brightness and color. Urgency for viewing from ground-based telescopes was vital to get the best data.

Combining the images from the FORS instrument on the ESO telescope using four different filters with those of other large telescopes, a team of astronomers led by Karen Meech of the Institute for Astronomy in Hawaii found that ‘Oumuamua varies in brightness by a factor of ten as it spins on its axis every 7.3 hours. No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width. The most elongated objects we have seen to date are no more than three times longer than they are wide.

“This unusually big variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape,” said Meech. We also found that it had a reddish color, similar to objects in the outer solar system, and confirmed that it is completely inert, without the faintest hint of dust around it.”

These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over hundreds of millions of years.

A few large ground-based telescopes continue to track the asteroid, though it’s rapidly fading as it recedes from our planet. Two of NASA’s space telescopes (Hubble and Spitzer) are tracking the object the week of Nov. 20. As of Nov. 20, ‘Oumuamua is travelling about 85,700 miles per hour (38.3 kilometers per second) relative to the Sun. Its location is approximately 124 million miles (200 million kilometers) from Earth — the distance between Mars and Jupiter – though its outbound path is about 20 degrees above the plane of planets that orbit the Sun. The object passed Mars’s orbit around Nov. 1 and will pass Jupiter’s orbit in May of 2018. It will travel beyond Saturn’s orbit in January 2019; as it leaves our solar system, ‘Oumuamua will head for the constellation Pegasus.

Observations from large ground-based telescopes will continue until the object becomes too faint to be detected, sometime after mid-December. NASA’s Center for Near-Earth Object Studies (CNEOS) continues to take all available tracking measurements to refine the trajectory of 1I/2017 U1 as it exits our solar system.

This remarkable object was discovered Oct. 19 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s Near-Earth Object Observations(NEOO) Program, which finds and tracks asteroids and comets in Earth’s neighborhood. NASA Planetary Defense Officer Lindley Johnson said, “We are fortunate that our sky survey telescope was looking in the right place at the right time to capture this historic moment. This serendipitous discovery is bonus science enabled by NASA’s efforts to find, track and characterize near-Earth objects that could potentially pose a threat to our planet.”

Preliminary orbital calculations suggest that the object came from the approximate direction of the bright star Vega, in the northern constellation of Lyra. However, it took so long for the interstellar object to make the journey – even at the speed of about 59,000 miles per hour (26.4 kilometers per second) — that Vega was not near that position when the asteroid was there about 300,000 years ago.

While originally classified as a comet, observations from ESO and elsewhere revealed no signs of cometary activity after it slingshotted past the Sun on Sept. 9 at a blistering speed of 196,000 miles per hour (87.3 kilometers per second).

The object has since been reclassified as interstellar asteroid 1I/2017 U1 by the International Astronomical Union (IAU), which is responsible for granting official names to bodies in the solar system and beyond. In addition to the technical name, the Pan-STARRS team dubbed it ‘Oumuamua (pronounced oh MOO-uh MOO-uh), which is Hawaiian for “a messenger from afar arriving first.”

Astronomers estimate that an interstellar asteroid similar to ‘Oumuamua passes through the inner solar system about once per year, but they are faint and hard to spot and have been missed until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them.

“What a fascinating discovery this is!” said Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory, Pasadena, California. “It’s a strange visitor from a faraway star system, shaped like nothing we’ve ever seen in our own solar system neighborhood.”

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Will asteroid Apophis hit Earth in 2036? NO! And here is why.

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When I woke up this morning my inbox was full. I received two dozen messages from concerned citizens who heard about asteroid Apophis in the news this morning. When I checked Google News, I found quite a few “news reports“ claiming NASA issued a warning that our planet will be hit by asteroid Apophis in 2036. Those recent news reports are absolutely false. NASA did not issue such a warning. Asteroid Apophis will not hit us in 2036. Read an in-depth article about Apophis by one of our experts, here.

I did email our Asteroid Day Expert Panel this morning and got three replies.

First reply by Dr. Clark Chapman:

“I would point out that the JPL CNEOS center *is* the official NASA site for predicted impacts. This link shows no impact possibility in 2036 for Apophis.  The highest impact probability (for a date in April 2068) is less than 1-in-100,000. Of course, there was a time, years ago, before more recent observations, when the possibility of Apophis impacting the Earth seemed to be much higher. But that is old news.“

Then Rusty Schweickart said:

“The probability that Apophis will impact Earth at any time in the next 100 years is, in fact lower than 1 in 100,000.  And we know this because we’ve been tracking Apophis now for over 10 years with resultant improvements in our knowledge of its orbit each time we see it.  Five years ago there was a very slight chance of a 2036 impact, but that, as Clark said, was based on our less accurate knowledge of its orbit back then.  This is precisely why we continue to track and update the orbits of all the asteroids we have discovered… and why we must continue to do so.

What is most important is to continue the search for those near-Earth asteroids out there that we haven’t ever seen yet.  Those are the potentially dangerous ones that will surprise us!  Apophis is not only old news, but if, at some time in the distant future (>100 years!) Apophis is indeed headed for a close call with Earth, we’ll know about it decades ahead of time and can easily take preventive measures.“
And Dr. Patrick Michel added:

“Just to add a piece of information, the 2036 impact was definitely ruled out thanks to observations in 2012-2013. It was then stated:

The new radar data, along with new optical astrometry, permits refinement of the 2036 Earth encounter, now nominally predicted to occur at a distant 0.388 au (about 150 lunar distances).“
see:
If you have any further questions then please visit our dedicated Expert page (here) where you can submit your questions to our experts.
Thank you,
Grig
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A meteoroid as seen from the Space Station

Paolo Nespoli, ESA meteoroid_lq

This article was originally written by the European Space Agency. Continue reading via ESA.int, here.

A series of night-time photos were taken by ESA astronaut Paolo Nespoli on 5 November around 22:33 GMT, here shown in a time-lapse with a 1-second interval, while the Space Station was flying from the southern Atlantic Ocean over to Kazakhstan. Paolo was lucky enough to capture a fast fireball falling to Earth over the Atlantic Ocean, off the South Africa west coast — look closely between 00:07 and 00:08 seconds at upper right in this video.

A fireball is basically a very bright meteoroid — a small bit of natural “space rock” — entering Earth’s atmosphere and burning brighter than the background stars. This particular meteoroid was moving much faster than typical, with an estimated speed of around 40 km/s, according to experts working on near-Earth objects (NEOs) in ESA’s Space Situational Awareness Programme.

 

Continue reading via ESA.int, here.

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The Leonid meteor shower lights up the sky tonight. Here’s how to watch.

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This article was written by Brian Resnick for Vox.com. Continue reading via Vox.com, here.

When Earth passes through the trail of debris left behind by a comet, bits of that debris catch fire in our atmosphere and streak across the sky in a blazing 3,000-degree flash. Friday and Saturday night, you can watch this in action by catching the annual Leonid meteor shower, which will run through the weekend.

The new moon on Saturday means the skies will be at their darkest. So it will be the better night to see a dozen or so meteors an hour.

They’re called Leonids because they appear to emanate out of the constellation Leo (the lion), which you can find rising in the eastern sky Friday and Saturday night. The meteors might be best seen in the very late overnight hours until dawn, as they rise higher and higher in the sky.

The meteors should be visible the world over. But where exactly to look will depend on where you are in the world. Here’s the view from Washington, DC, at 1:25 am Saturday. They’ll be close to the horizon in the east. (Use a location-based sky map app like Sky Guideto figure out exactly when and where to look where you live.)

Continue reading this article via Vox.com, here.

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Interstellar asteroid is given a name

Oumuamua_interstellar_asteroid

This article originally appeared on BBC.com. Continue reading it here.

The first known asteroid to visit our Solar System from interstellar space has been given a name.

Scientists who have studied its speed and trajectory believe it originated in a planetary system around another star. The interstellar interloper will now be referred to as ‘Oumuamua, which means “a messenger from afar arriving first” in Hawaiian. The name reflects the object’s discovery by a Hawaii-based astronomer using an observatory on Maui. It was discovered on 19 October this year by Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy.

Weryk and fellow Institute for Astronomy researcher Marco Micheli realised it was going extremely fast (with enough speed to avoid being captured by the Sun’s gravitational pull) and was on a very eccentric trajectory taking it out of our Solar System.

Continue reading (via BBC.com)

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Astronomers Complete First International Asteroid Tracking Exercise

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This originally appeared on NASA.gov on November 3, 2017. Continue reading via NASA.gov here.

An international team of astronomers led by NASA scientists successfully completed the first global exercise using a real asteroid to test global response capabilities.

Planning for the so-called “TC4 Observation Campaign” started in April, under the sponsorship of NASA’s Planetary Defense Coordination Office. The exercise commenced in earnest in late July, when the European Southern Observatory’s Very Large Telescope recovered the asteroid. The finale was a close approach to Earth in mid-October. The goal: to recover, track and characterize a real asteroid as a potential impactor — and to test the International Asteroid Warning Network for hazardous asteroid observations, modeling, prediction and communication.

The target of the exercise was asteroid 2012 TC4 — a small asteroid originally estimated to be between 30 and 100 feet (10 and 30 meters) in size, which was known to be on a very close approach to Earth. On Oct. 12, TC4 safely passed Earth at a distance of only about 27,200 miles (43,780 kilometers) above Earth’s surface. In the months leading up to the flyby, astronomers from the U.S., Canada, Colombia, Germany, Israel, Italy, Japan, the Netherlands, Russia and South Africa all tracked TC4 from ground- and space-based telescopes to study its orbit, shape, rotation and composition.

Continue reading on NASA.gov

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Dinosaurs would have survived if asteroid hit Earth elsewhere, scientists claim

Yaluts’il Cenote (sinkhole)/Yucatan Peninsula/Mexico

This is an excerpt from a Washington Post article. Click here to read the full article.

When the cosmos shoots pool, it plays for keeps. It sank a six-mile-wide rock in our pocket of the solar system 66 million years ago. The smack of the asteroid against Earth released energy on the order of billions of atomic bombs. Dinosaurs were the cataclysm’s most famous victims, joined by sea creatures, plants and microorganisms. All told, Earth’s biodiversity shrank by 75 percent in what is known as the Cretaceous-Paleogene, or K-Pg, extinction (also known as the K-T extinction).

A large asteroid strike happens only once every 100 million years. And a controversial new report suggests the K-Pg impact was an exceptionally unlikely shot. In a paper published Thursday in the journal Scientific Reports, a pair of researchers calculated the asteroid had little more than a 1-in-10 chance of triggering a mass extinction when it smacked into Earth. (We mammals should be glad it beat the odds: After the dinosaurs’ swift exit, nocturnal furballs — our ancestors — scampered into the daylight and conquered the planet. And one branch of dinosaurs survived and persists as today’s birds.)

Soot was the impact’s most lethal symptom, argued paleontologist Kunio Kaiho, of Tohoku University, and Naga Oshima, an atmospheric chemist at Japan’s Meteorological Research Institute. The asteroid hit Earth near the Yucatán Peninsula in Mexico. There, the researchers say, vast reservoirs of crude oil and hydrocarbons were tucked beneath a shallow sea, waiting to be set ablaze.

Continue reading (via Washington Post)

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