Astronomers today have discovered a second mysterious, likely interstellar object on a path through our solar system.
Why it matters: These interlopers – the first of which originated in the inner solar system in 2017 – represent the best chance astronomers are far from learning more about distant star systems from close range.
- "This is the only thing in astrophysics where you have a piece of space that comes to you," astronomer planet Michele Bannister told Axios.  What's happening: Last week, scientists announced the discovery of a likely interstellar comet.
- NASA now predicts the comet will fly nearly 190 million miles from Sunday in close proximity to December before exiting the solar system again.
- Unlike & # 39; Earlier, the first interstellar object, this comet – C / 2019 Q4 (Borisov) – was visible for almost a year, giving astronomers time to study the structure, composition and path throug h the galaxy.
Details: Some scientists focus on the comet's atmosphere, known as a coma, created when the object eats as it approaches the Sun. The heat causes the comet's ice to turn immediately from solid to gas.
- Scientists hope to put together what kind of ice exists on the comet – and the volume – by watching how the sunlight hits the coma.
- Early results from observations taken by Gran Telescopio Canarias show that the composition of the C / 2019 Q4 may be similar to the comets seen in our solar system.
- If comet chemistry matches what astronomers have found in comets elsewhere in our solar system, it may indicate that part of the space in which comets are formed may resemble the chemistry of our solar system.
"This, to me, is relevant, & # 39; Are all solar systems suitable for life? & # 39;"
– Karen Meech, an astronomer at the University of Hawaii, told Axios
Background: Scientists expect to compare & # 39; General and C / 2019 Q4 to find out how unique or similar these 2 things are to come from 2 parts of the galaxy.
- In particular, they will try to compare the shape of the C / 2019 Q4 to the unique tobacco-like structure of & # 39; Oumheula, which looks different to anything we have yet seen in our solar system.
What's next: Some scientists expect to create a protocol for every next interstellar comet located to maximize their chances of being observed as soon as possible.
- The Large Synoptic Survey Telescope, expected to arrive online next year. must see interstellar objects while flying through our solar system.
- The mission of the European Space Agency's Comet Interceptor – expected to launch in 2028 – may disrupt an interstellar comet when it is in place and ready after its expected launch in 2028.
The big picture: Even without the new tools online, C / 2019 Q4 gets a glimpse of just 2 years after seeing & # 39; Oumheula deepening the mystery around just how many interstellar objects can visit our solar and stem.
- It is possible that these things pass through our solar system more often than scientists think, but only 2 have found that scientists are now unable to tell whether that is actually the case or not.
- "Maybe our understanding is different. Maybe we're just lucky. Maybe there's a new mystery here. We don't know," space scientist Carrie Nugent told Axios.