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To Jason Davis
Maybe & # 39; Oumuamua was not the first visitor to another star system after all.
When the mysterious, stadium-sized object passed by our sun in 201
The newspaper's authors, Harvard astronomer Avi Loeb and Harvard student Amir Siraj, collected data from a worldwide network of US government sensors scanning the sky for rockets, instead searching for meteors move fast enough to come from outside our solar system. They found a knife-sized object that rammed into the earth at a speed of 60 km / s, and the pursuit of its path concluded that it came from interstellar space.
It is assumed that the object was resolved prior to reaching the ground, but its existence raises the possibility that firsthand interstellar objects can be examined. Loeb said the government system could be modified to warn scientists when a fast-moving meteor is discovered, so they can search for fragments that have survived all the way to the ground.
"It's a new way to search interstellar objects". said Loeb, who raised his eyebrows in 2018 when he said that Oumuamua could be an alien spaceship. "It saves you travel, you do not have to go to another planetary system, you get material objects that you may be able to examine."
If the discovery of the meteor is confirmed, it means that our solar system was visited by two interstellar objects in a span of only three years. Loeb said it must mean that there should be at least a million more objects that we never see whizzing through the inner solar system and that an interstellar meteor hits Earth every 10 years.
Life on Earth
Astronomers have long hypothesized that asteroids or comets could have transported the organic molecules that became the building blocks of life to the ancient earth. But there is no rule that says they had to come from our own solar system.
Asteroids are rockier, while comets are more icy. "Oumuamua looked like an asteroid, but moved like a comet and spit out gas. As soon as one of these objects enters our atmosphere, it becomes a meteorite, and every piece that survives all the way to the ground becomes a meteorite.
The potential discovery of an interstellar meteorite holds a fascinating possibility: Scientists might be able to investigate interstellar meteorites to see if they can transport life between star systems.
"We suspected that panspermia, sowing life between planets and planetary systems, can help spread life in our galaxy," said Franck Marchis, a high-level planetary astronomer at the SETI Institute in Mountain View, California , "It will be great to get a fragment from [an interstellar meteor] to really understand the conditions of the long journey between stars."
He added that such a journey could take millions of years and all organic molecules should be good – protected to survive.
Just a simple old meteor?
Not everyone is convinced that the meteor identified by Loeb and Siraj originated outside our solar system. The government will not say how accurate their sensors are, so it is impossible to know exactly how the actual speed and direction of the object coincides with that reported.
"I do not think we can rule out the bound [inside our solar system] trajectories beyond the available evidence" said the astronomer Quanzhi Ye of the California Institute of Technology on Twitter . Peter Brown, a meteor astronomer at the University of Western Ontario, called the uncertainties a "huge red flag," adding, "It's very difficult to measure orbits and velocities with sufficient accuracy to be able to say definitively," This particular is interstellar. "
Loeb and Siraj address the uncertainties in their article and refer to two earlier studies comparing state sensor data with results from known calibrated sensors could drop to 28 percent, but Loeb said a 45 percent speed error would be required for the Papua New Guinea meteor to come out of the solar system.
Scientists may eventually be able to use telescopes Using special equipment to see interstellar meteorites burn in the atmosphere and decode their compositions from the traces of the burning gas they leave behind, this could mean more opportunities for scientists studying asteroids and comets to do more to learn about the emergence of other star systems.
a postdoctoral fellow The Queen's University Belfast in Northern Ireland. "Was this the same as with other stars? That's the basic process we're trying to dig here: how did the building blocks of the planets originate and emerge?"
Bannister said that she has not convinced the meteor of Papua New Guinea from outside the solar system, "but they pose the right scientific question," she said of Loeb and Siraj.
In an unpublished paper, Loeb suggests that interstellar meteors may be a way for aliens to communicate with Earthlings. However, he admits that the idea is far-fetched: "Some of them could even be a piece of technical equipment from alien civilizations that happened to migrate to Earth, just like a plastic bottle swept ashore against natural shells."
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