Mysterious ‘Oumuamua’ space object has finally been identified

(THIS ARTICLE IS COURTESY OF NBC NEWS AND ‘MARCH’)

 

Mysterious ‘Oumuamua’ space object has finally been identified

Astronomers say the cigar-shaped interstellar visitor isn’t an asteroid, but a comet.
by David Freeman / 
Image: Oumuamua

Observations show that the interstellar visitor “Oumuamua” was traveling through space for millions of years before its chance encounter with our star system.M. Kornmesser/European Southern Observatory / NASA

When astronomers first spied a weird cigar-shaped object speeding past the sun last October, they could tell from its path that it had come from another star system — but they didn’t know exactly what it was.

Now they know. A study published Wednesday in the journal Nature indicates that the interstellar visitor, dubbed Oumuamua, is neither an asteroid nor an alien spacecraft (as some wags had suggested) but a small interstellar comet.

“It’s the only such object discovered so far,” Marco Micheli, an astronomer with the European Space Agency and the lead author of the new study, told NBC News MACH in an email.

Image: Oumuamua
This artist’s illustration shows ‘Oumuamua racing toward the outskirts of our solar system, and is annotated with the locations of the planetary orbits. As the complex rotation of the object makes it difficult to determine the exact shape, there are many models of what it could look like.JPL / NASA

Comets — icy, dusty objects that have been likened to “dirty snowballs” — typically form long tails when they come close to the sun. No such tail was visible in earlier observations of Oumuamua (which means “scout” in Hawaiian), a fact that helped lead other astronomers to conclude that it was an asteroid.

But an analysis of new observations made by ground-based telescopes and the Hubble Space Telescope yielded a surprise: Oumuamua’s trajectory couldn’t be explained solely by the gravitational forces exerted on it by the sun and the planets — as would be the case if it were an asteroid, or space rock.

“Unexpectedly, we found that Oumuamua was not slowing down as fast as it should have under gravitational forces alone,” Micheli said in a statement.

His team concluded that the unexpected motion of Oumuamua had to be caused by the spewing out of small quantities of gaseous materials from its surface. This “outgassing” — commonly seen in comets — was too small to be visible but significant enough to affect Oumuamua’s trajectory.

But not everyone is buying that explanation — at least not completely.

Alan Jackson, an astronomer at the University of Toronto Scarborough, told MACH in an email that if Oumuamua is a comet, it must be one that lost much of its ice before leaving its home star system.

“A comet that has lost enough of its ice is essentially the same as an asteroid,” he said. “Oumuamua thus seems to be in that ambiguous region between the two.”

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Jackson conducted previous research on Oumuamua but was not involved in the new study.

Whatever its precise identity, Oumuamua might be just the first of many such interstellar visitors we’ll encounter. Jackson said new telescopes should help astronomers find “a lot more objects like Oumuamua and we will then be able to put together a more complete picture of what the building blocks of planets look like in other planetary systems, which will also help us to understand how planets form.”

Oumaumau is now headed to the outer solar system at a speed of about 70,000 miles per hour. Astronomers expect it to pass Neptune’s orbit in four years.

“The object is now too faint to observe, so no new data will be acquired,” Micheli said in the email. “But I expect scientists will keep working on their data for quite some time.”

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Asteroid on Course to Earth Was Spotted Just Hours Before It Hit The Atmosphere

(THIS ARTICLE IS COURTESY OF THE WASHINGTON POST)

 

Asteroid on Course to Earth Was Spotted Just Hours Before It Hit The Atmosphere

Surprise!

ALEX HORTON, THE WASHINGTON POST
5 JUN 2018

Witnesses reported a fireball streaking across the sky above Botswana on Saturday night.

The asteroid hurtling toward Earth at 10 miles (16 km) a second looked like it could be the harbinger of catastrophe. A webcam in a rural area west of Johannesburg captured it, showing a luminous orb igniting the sky in a bright flash.

NASA had only discovered the asteroid on Saturday and determined it was on a collision course for the planet, charted for entry in a vast expanse from Southern Africa and across the Indian Ocean to New Guinea and given the name 2018 LA.

The reality of the asteroid’s fiery end was less dramatic than the video shows. The asteroid was estimated at just six feet (1.8 metres) across, otherwise known as boulder-sized, NASA’s Jet Propulsion Laboratory said in a statement.

It burned up “several miles” above the Earth’s surface.

NASA and space enthusiasts do not get many opportunities like this. Asteroid 2018 LA was only the third asteroid discovered on an impact trajectory, the agency said, and just the second time a high probability of impact was determined ahead of time.

The last predicted impact was asteroid 2014 AA, and it too was discovered only hours before it entered the atmosphere over the Atlantic Ocean on New Year’s Day in 2014, NASA said.

“[T]his real-world event allows us to exercise our capabilities and gives some confidence our impact prediction models are adequate to respond to the potential impact of a larger object,” said Lindley Johnson, an official at NASA’s Planetary Defense team, which tracks and warns of asteroids that may pose a threat to the planet.

KFDLE7J3A4ZMJHHOSXVO67EJUAThe discovery observations of Asteroid 2018 LA. (NASA/JPL-Caltech/CSS-Univ. of Arizona)

Asteroids are small remnants of violent collisions in the solar system’s history and formed around 4.5 billion years ago.

They are typically composed of rock-forming minerals like olivine and pyroxene but often contain iron and nickel, NASA said.

The Asteroid Belt between Mars and Jupiter contains hundreds of thousands of asteroids more than half a mile in size or more, with millions of smaller objects tumbling in space.

Asteroid 2018 LA was first discovered by the NASA-funded Catalina Sky Survey operated by the University of Arizona, the agency said. NASA linked to the video in its statement, and the publisher said on YouTube the video is from his father’s South African farm.

NASA relies on a patchwork of observers to track what it calls near-Earth asteroids, the agency explained in a video.

Constantly scanning telescopes capture images of the sky and movement through photos over time triggers a comparison of known objects in a database.

If the object is unknown, the agency will review the object and expedite the analysis if experts determine it will streak close to the Earth. Astronomers from NASA, other space agencies and even amateur enthusiasts then join in to refine the trajectory.

2018 © The Washington Post

This article was originally published by The Washington Post.

Mystery Object May Be Our First Visitor From Another Solar System

(THIS ARTICLE IS COURTESY OF CNN)

 

This mystery object may be our first visitor from another solar system

(CNN)Astronomers around the world are trying to track down a small, fast-moving object that is zipping through our solar system.

Is a comet? An asteroid? NASA’s not sure. The space agency doesn’t even know where it came from, but it’s not behaving like the local space rocks and that means it may not be from our solar system.
If that’s confirmed, NASA says “it would be the first interstellar object to be observed and confirmed by astronomers.”
“We have been waiting for this day for decades,” Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies, said in a NASA news release. “It’s long been theorized that such objects exist — asteroids or comets moving around between the stars and occasionally passing through our solar system — but this is the first such detection. So far, everything indicates this is likely an interstellar object, but more data would help to confirm it.”
NASA says astronomers are pointing telescopes on the ground and in space at the object to get that data.
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For now, the object is being called A/2017 U1. Experts think it’s less than a quarter-mile (400 meters) in diameter and it’s racing through space at 15.8 miles (25.5 kilometers) per second.
It was discovered October 19 by the University of Hawaii’s Pan-STARRS 1 telescope on Haleakala, Hawaii.
Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy, was the first to identify the object and immediately realized there was something different about it.
“Its motion could not be explained using either a normal solar system asteroid or comet orbit,” he said. “This object came from outside our solar system.”
Whatever “it” is, the object isn’t a threat to Earth.
NASA say that on October 14, it safely passed our home world at a distance of about 15 million miles (24 million kilometers) — that’s about 60 times the distance to the moon.
Where’s it going? Scientists think the object is heading toward the constellation Pegasus and is on its way out of our solar system.
“This is the most extreme orbit I have ever seen,” said Davide Farnocchia, a scientist at the Center for Near-Earth Object Studies. “It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back.”
“It” may eventually get a better name than A/2017 U1, but since the object is the first of its kind, the International Astronomical Union will have to come up with new rules for naming the object.