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Home / Science / Watertown Daily Times | It is a comet! No, it's an asteroid! No, it's an alien spaceship! (Actually, it's a comet.)

Watertown Daily Times | It is a comet! No, it's an asteroid! No, it's an alien spaceship! (Actually, it's a comet.)



A mysterious, strangely elongated object that shines through our solar system is probably a comet. This is the conclusion of astronomers using the Hubble Space Telescope and 27 ground-based telescopes to study the interstellar visitor that was discovered on 19 October. It is the first object ever created outside our planetary neighborhood.

Report published in the journal Nature on Wednesday will not close the book on what was called Oumuamua, because the Hawaiian word means "boy scout." Even if it's a comet, it's funny.

Oumuamua with a telescope in Hawaii, they fought to classify it. A comet seemed to be the best estimate because such things are predicted by theorists to routinely arrive from outer space. But it did not look like a comet. It lacked a visible atmosphere. It had no coma, no tail.

Astronomers quickly changed the classification from comet to asteroid and then changed it back to "interstellar object". It is the only member of this exclusive club.

Predictably, the mysterious object is invited speculation ̵

1; at least among those with a speculative inclination – that it could be artificial. Science fiction fans noted that Arthur C. Clarke's 1973 novel Rendezvous With Rama focused on an alleged interstellar asteroid that turns out to be a giant extraterrestrial spaceship. Although alleged aliens are a recurrent nuisance to serious scientists, in this case, there was enough eeriness for Oumuamua that some astronomers used the large radio telescope at the West Virginia Green Bank to see if it might send signals.

It did not look like a comet at any point in its journey. But his movement through the solar system indicated that it released gas from its interior when heated by the sun, the report in Nature said. By observing the object for many weeks from several telescopes, astronomers were able to detect the signature of a subtle acceleration change that coincides with the outgassing of the comet.

"We examined a variety of possible physical mechanisms to explain the acceleration we discovered, and we found that the comet-like outgassing works well while the others can be excluded," said lead author Marco Micheli, astronomer at one European Space Agency in Frascati, Italy via e-mail.

So why not it appears cometary? One of the coauthors of the paper, Karen Meech, an astronomer from the University of Hawaii, said tiny dust grains, typically lying on the surface of comets and blown out by gassing, may have been eroded during Oumuamua's journey through the galaxy. Larger dust grains would have remained, but they would be much less numerous and harder to discover, she said.

Astronomers searched for the chemical signature of cyanide, which is typically ejected from comets along with water. They did not see anyone. This may be a data point about the diversity of solar systems in our galaxy, Meech said.

"We see that not all solar systems will have the same chemical constituents when assembled together," she said. "This is again what we would expect, but this is our first rehearsal."

Other astronomers are unwilling to rest the secret.

"I'll wait with interest for the submission of the data to run my own analysis and see what I think," said Gareth Williams, an astronomer with the Minor Planet Center Harvard-Smithsonian.

"I think they found something interesting, but I'm not sure it's quite as clear as it is presented in the paper," said Alan Jackson, an astronomer at the University of Toronto, in an email , Jackson, who wrote a co-brief earlier this year describing Oumuamua as an asteroid ejected from a binary star system, noted this week that it is "a somewhat ambiguous object." The terms comets and asteroids are themselves a bit The original, strict distinction between asteroids and comets is whether or not they have a visible coma, and from this perspective, "Oumuamua is an asteroid because it does not exist."

This view was made repeated by NASA-Ames senior scientist David Morrison The research center said that the distinction between a comet and an asteroid may be a bit "blurry." Sometimes an object can evolve over time-more and more like one or the other the other,

This object is still something special case. "It has two unique things. It's the first object we've ever seen of any other solar system, and its shape is unlike anything we've ever seen, "Morrison said," No one can say exactly what the dimensions are, but the best guess is Meech. "Cigar Form" was the usual description.

Oumuamua entered the solar system after traveling the Void at 59,000 miles per hour Due to the sun's gravitational field, it accelerated in September, not yet seen by the Earthlings and approaching the sun – about 24 million miles – and reaching a top speed of 196,000 miles per hour, next month being close enough on Earth – 20 million miles – to be discovered by astronomers at Haleakala Observatory on Maui.

His age is unknown, the object could be plausibly the oldest, ever discovered in our solar system – older than the planets, moons, asteroids, and comets that formed with the Sun about 4.6 billion years ago. It could have been ejected from a different solar system than it was billions of years ago. In our own solar system, comets can be accelerated both through the gravitational field of Jupiter and through the sun and into the interstellar space.

One of the authors of natural paper, Paul Chodas of the Jet Propulsion Laboratory of NASA, has studied the comets thoroughly for decades, hoping to find a distinctly interstellar origin. He had failed. Then came Oumuamua.

"It immediately looked like an asteroid," Chodas said Monday. After several days of observing the object, astronomers realized that their trajectory and speed indicated that it must have come from outside our solar system. The Minor Planet Center at Harvard called it 2017 U1 Asteroid.

But in December, another turn came when Micheli discovered something strange in his movement, suggesting that a factor other than solar gravitation influenced the acceleration.

Chodas Knows The Alien Spaceship Mass may not be fully satisfied with the scientific explanation that includes natural outgassing. "It does not behave like a rocket or spaceship, it behaves like a comet, that's the first thing I have to say," he said Tuesday. "Second, interstellar space has only billions of billions of these objects ejected in the formation of different solar systems."

What you can learn at this point about Oumuamua, you have to deduce from the data already collected, because at 1 o'clock on Wednesday it was already 595 million miles from Earth, 13 times as weak as anything Hubble Space Detect Telescope and lead to the center of the galactic nowhere.

It is further from the Sun than the planet Jupiter, and a few years from now it will be further from the Sun than Neptune. The gravity of the sun slows it down, but not enough to hold it. With some symmetry, it will eventually reach its interstellar cruising speed of 59,000 mph when approaching the constellation Pegasus.

Theoretically, a spacecraft could be launched to catch up with "Oumuamua" and have a close look. But do not count on it in times of tight budgets. Whatever the thing is, it goes away – and it will not be back.


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