Oct 15, 2019

An interstellar comet revealed

Comet 2I/Borisov. Photo: Gemini Observatory/NSF/AURA

The interstellar comet discovered in August looks very similar to comets originating in our own solar system, according to a new study in Nature Astronomy this week.

The big picture: Comet 2I/Borisov represents just the second-known interstellar object to make its way through our solar system, and it's astronomers' best chance so far to study a piece of a distant star system at close range.

  • Even if it does turn out that the comet is just like those native to our solar system, it will show astronomers that other planetary systems light-years from our own likely formed in similar ways.

What they found: Unlike the strange cigar shape of the first interstellar object — named 'Oumuamua and seen in 2017 — 2I/Borisov has a pronounced dust tail and a reddish color that can be compared to other comets, according to the study.

  • "In combination with what we have learned from peculiar `Oumuamua, it tells us that there may be a lot of diversity in other planetary systems and the formation of minor bodies," Piotr Guzik, one of the authors of the new study, told Axios via email.
  • The team began its observations of the comet on Sept. 10, using the Gemini North Telescope in Hawaii and the William Herschel Telescope in Spain.
"This is a quick first look at the object and is showing what everyone has seen who has been observing this."
— University of Hawaii astronomer Karen Meech, who did not take part in the study, told Axios via email

What to watch: Astronomers will be keeping a close eye on 2I/Borisov as long as it's visible from Earth.

  • An earlier study submitted to The Astrophysical Journal Letters found cyanogen, a common molecule in solar system comets, in 2I/Borisov's atmosphere.
  • However, the comet still isn't in the perfect position to be able to get a good look at its chemical signature yet.
  • As the object gets closer — with its closest flyby of the Sun expected in early December — scientists should be able to piece together the chemical makeup of the comet's atmosphere and figure out just how familiar or alien it really is.

Go deeper

Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Global: Total confirmed cases as of 3 a.m. ET: 5,410,228 — Total deaths: 345,105 — Total recoveries — 2,169,005Map.
  2. U.S.: Total confirmed cases as of 3 a.m. ET: 1,643,499 — Total deaths: 97,722 — Total recoveries: 366,736 — Total tested: 14,163,915Map.
  3. World: White House announces travel restrictions on Brazil, coronavirus hotspot in Southern Hemisphere Over 100 coronavirus cases in Germany tied to single day of church services — Boris Johnson backs top aide amid reports that he broke U.K. lockdown while exhibiting symptoms.
  4. Public health: Officials are urging Americans to wear masks headed into Memorial Day weekend Report finds "little evidence" coronavirus under control in most statesHurricanes, wildfires, the flu could strain COVID-19 response
  5. Economy: White House economic adviser Kevin Hassett says it's possible the unemployment rate could still be in double digits by November's election — Public employees brace for layoffs.
  6. Federal government: Trump attacks a Columbia University study that suggests earlier lockdown could have saved 36,000 American lives.
  7. What should I do? Hydroxychloroquine questions answeredTraveling, asthma, dishes, disinfectants and being contagiousMasks, lending books and self-isolatingExercise, laundry, what counts as soap — Pets, moving and personal healthAnswers about the virus from Axios expertsWhat to know about social distancingHow to minimize your risk.
  8. Other resources: CDC on how to avoid the virus, what to do if you get it, the right mask to wear.

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Updated 2 hours ago - Politics & Policy

U.S. coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Andrew Witherspoon/Axios. This graphic includes "probable deaths" that New York City began reporting on April 14.

The CDC is warning of potentially "aggressive rodent behavior" amid a rise in reports of rat activity in several areas, as the animals search further for food while Americans stay home more during the coronavirus pandemic.

By the numbers: More than 97,700 people have died from COVID-19 and over 1.6 million have tested positive in the U.S. Over 366,700 Americans have recovered and more than 14.1 million tests have been conducted.

World coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Axios Visuals

Japan's economy minister outlined plans on Monday to end the nationwide state of emergency as the number of new novel coronavirus cases continues to decline to fewer than 50 a day, per Bloomberg. Japan has reported 16,550 cases and 820 deaths.

By the numbers: Over 5.4 million people have tested positive for the virus as of Monday, and more than 2.1 million have recovered. The U.S. has reported the most cases in the world (over 1.6 million from 13.7 million tests). The U.K. is reporting over 36,800 deaths from the coronavirus — the most fatalities outside the U.S.