Home / Science / Watertown Daily Times | It's a comet! No, it's an asteroid! No, it's a strange space ship! (It's actually a comet.)

Watertown Daily Times | It's a comet! No, it's an asteroid! No, it's a strange space ship! (It's actually a comet.)



A mysterious strange elongated object that stretches through our solar system is probably a comet. It is the conclusion of astronomers who used the Hubble Space Telescope and 27 ground-based telescopes to review the interstellar visitor, which was first discovered on October 19th. It is the first object ever seen as originating from our planet area.

Their new report, published Wednesday in the journal Nature, will not close the book about what is called "Oumuamua, for the Hawaiian word" scout. "Although it's a comedy it's strange.

After astronomers discovered" Oumuamua with a telescope in Hawaii, they struggled to classify it. A comet seemed the best guess, because such things are predicted by theorists to come out of the deeper space routinely. 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 the comet to the asteroid and then changed it to "interstellar objects". It is the only member in the exclusive club.

Predictable, the subject of the mystery is urgent speculation ̵

1; at least among them with a speculative curve – that it could be artificial. Science fiction fans noted that Arthur C. Clark's 1973 novel "Rendezvous With Rama" centers on an alleged asteroid from interstellar space which, after closer inspection, proves to be a giant primarily Roman spacecraft. Although supposed aliens are a recurring inconvenience to serious scientists, in this case it was sufficiently strange that "Oumuamua that some astronomers used the big radio telescope in Green Bank, West Virginia, to see if it could signal."

The did not look like a comet at any time of the journey, but its motion through the solar system suggested that it emitted gas from its interior when heated by the sun, according to the report in nature. By observing the object for several weeks from several telescopes, astronomers could retrieve the signature of a subtle change in acceleration consistent with cometic exhaustion.

"We investigated a variety of possible physical mechanisms to explain the acceleration we discovered, and we found that comet-like degassing works well, while the others can be ruled out," said the author Marco Micheli , an astronomer at a European Space Workshop in Frascati, Italy, p eight by e-mail.

So why does not it seem cometic? One of the co-authors of the paper, Karen Meech, a Hawaiian astronomer, said that small dust particles that are typically found on the comets and blown away by degassing may have been endure during Oumuamuas journey across the galaxy. Larger dust cows would have remained, but they would be much fewer and more difficult to detect, she said.

Astronomers were looking for the chemical signature of cyanide, which is usually sprayed from comets along with water. They saw no one. It is potentially 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 ingredients when they are assembled," she said. "What's again what we can expect, but this is our first test."

Other astronomers are not ready to let the mystery rest.

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

"I think they've found something interesting, but I'm not sure it's as clear as it's featured in the magazine," said Alan Jackson, a Toronto-astronomical director, in an email. year co-wrote a paper describing "Oumuamua as an asteroid emitted from a double star system, noted this week that it" is a somewhat ambiguous object. The terms comet and asteroid are themselves a little ambiguous. The original strict distinction between asteroids and comets is whether they have a visible coma, and from that perspective, "Oumuamua is an asteroid because it did not."

This perception was echoed by senior researcher David Morrison from NASA's Ames Research Center, who said the difference between a comet and an asteroid could be a little "fuzzy." Sometimes an object can evolve over time – becomes more like one or the other, he said.

This item is still special in any case. " has two unique things. It's the first thing we've ever seen from another solar system, and its shape is unlike what we've ever seen, "Morrison said. Nobody can say exactly what the dimensions are, but the best estimate is that it's half a mile long and only one tenth of it in diameter, according to Meech. "Cigar shaped" has been the common description.

Oumuamua entered the solar system after crossing through the void at 59,000 miles per hour. As it approached due to the sun's gravity. In September, still invisible by Earthlings, it made its closest approach to the sun – about 24 million miles. It also reached a peak of 196,000 miles per hour. On its outbound leg next month it came close to Earth – 20 million miles – to be detected by astronomers at the Haleakala Observatory on Maui.

Age is unknown. The object may probably be the oldest ever discovered in our solar system – older than the planets, the moon, the asteroids and the comet, formed together with the sun 4.6 billion years ago. It could have been emitted from another solar system when it was formed billions of years earlier. In our own solar system, comets can be accelerated by Jupiter's gravitational field, as does the sun and reach airspace, which intervenes in interstellar space.

One of the natural paper co-authors, Paul Chodas of NASA's Jet Propulsion Laboratory, had carefully researched comets for decades, hoping to find one with a clear interstellar origin. He had failed. Then came "Oumuamua."

"It immediately looked like an asteroid," said Chodas monday. After several days as observed the object, astronomers realized that its speed and speed showed that it must have come from beyond our solar system. The Minor Planet Center at Harvard is called the Asteroid 2017 U1.

But in December another twist came when Micheli discovered something odd in his motion that suggested another factor than the sun's gravity affects the acceleration.

Chodas knows the Alien-spaceship audience may not be completely satisfied with the scientific explanation that involves natural exhaustion. "It does not seem like a rocket or a spacecraft. It's like a comet." It's the first to say, "he said Tuesday." Secondly, interstellar space has only countless billions of these objects thrown into the formation of different solar systems. "

Whatever can be learned at this time," Oumuamua must be separated from data already collected, because at 1 o'clock on Wednesday there were already 595 million miles from the earth, 13 times as weak as anything Hubbel's space telescope could detect and lead to the middle of the galactic nowhere.

It is already farther from the sun than the planet Jupiter and for a few years it will be farther from the sun than Neptune. The gravity of the sun slows it but not enough to keep it. With dirty symmetry, it will eventually resume its interstellar speed at 59,000 mph, as it leads to the constellation Pegasus.

In theory, a space probe can be launched to catch up with "Oumuamua and take a closer look. Do not count on it in a time of flat space budgets, but. Anyway, it goes away – and it will not be back.


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