[New Tang Dynasty Beijing time, March 25, 2023]The mysterious celestial body “Oumuamua” (Oumuamua) is the first interstellar object discovered to visit the solar system. Since it was observed in 2017, ‘Oumuamua has attracted the attention of scientists for many of its eerie properties, including its strange acceleration as it moves away from the sun.
Scientists have discovered that the phenomenon of “Oumuamua” moving away from the sun at an increasing speed cannot be explained according to the conventional gravitational theory. Given its unexpected behavior, scientists have come up with various theories, including that it may actually be an alien spacecraft.
A new study offers a clearer explanation: ‘Oumuamua’s accelerating behavior is due to the hydrogen it releases as it heats up in sunlight, Reuters reported on March 23.
Scientists initially thought ‘Oumuamua was a comet from an outer planet. But later observations revealed that it lacked the tail of gas and dust that characterizes many comets. It was previously described as being in the shape of a cigar, but is now thought to resemble a rock pancake. It was smaller than originally estimated and has now been determined to be about 375 feet (115 meters) long, 365 feet (111 meters) wide and about 60 feet (19 meters) thick.
After being somehow flung out of the solar system, ‘Oumuamua’s chemical composition changed as it was bombarded with high-energy radiation as it traveled through interstellar space, scientists say. This converted some of its ice — frozen water — into hydrogen gas, but the hydrogen gas was trapped in the rest of the ice.
‘Oumuamua was heated as it passed through our inner solar system, causing its icy structures to rearrange and release trapped hydrogen gas, which gave ‘Oumuamua a little kick as it traveled farther from the sun. In a process known as outgassing, this release of hydrogen gas does not result in a visible comet tail.
“The key finding is that ‘Oumuamua likely started as a small water-rich icy body, roughly similar to solar system comets,” said Jenny Bergner, an astrochemist at the University of California, Berkeley. This model can explain ‘Oumuamua’s strange behavior without resorting to any fancy physics or chemistry.”
Bergner is the lead author of the study, which was published this week in the scientific journal Nature.
‘Oumuamua was first discovered by the University of Hawaii’s Pan-STARRS1 telescope. Its name means “messenger from afar” in the Native Hawaiian language.
“We don’t know where it originated, but it probably traveled in interstellar space for less than 100 million years. It has a reddish color that matches the color of many small bodies in the solar system. It is currently passing Neptune on its way out of the solar system. said Bergner.
In 2019, the Hubble Space Telescope of the National Aeronautics and Space Administration (NASA) photographed the second exoplanet to visit the solar system, the comet “2I/Borisov”. Compared to ‘Oumuamua, the object looks and behaves more like a typical comet. Its photos reveal the dust surrounding the comet’s nucleus.
Once a new astronomical observatory now under construction in Chile becomes operational next year as planned, one or two interstellar objects could be discovered in the solar system each year, the researchers said.
(Reposted from The Epoch Times/Editor in charge: Ye Ping)
