Parker Solar Probe Gives a Unique Perspective on Comet NEOWISE

Comet watchers have enjoying the newly-discovered NEOWISE comet since it was first spotted in March 2020. Now that it’s visible with the naked eye, in dark sky conditions, all kinds of Earthly observers are checking the visitor out.

But NASA’s Parker Solar Probe has another view of the comet, one denied to Earth-bound observers.

Continue reading “Parker Solar Probe Gives a Unique Perspective on Comet NEOWISE”

Interstellar Comet 2I/Borisov Formed in a Very Cold Environment

In the summer of 2019, a team of astronomers from NASA, the ESA, and the International Scientific Optical Network (ISON) announced the detection of the comet 2I/Borisov. This comet was the only second interstellar visitor observed passed through our Solar System, coming on the heels of the mysterious ‘Oumuamua. For this reason, astronomers from all over the world watched this comet intently as it made its closest pass to the Sun.

One such group, led by Martin Cordiner and Stefanie Milam of NASA’s Goddard Space Flight Center, observed 2I/Borisov using the ESO’s Atacama Large Millimeter/submillimeter Array (ALMA) in the Chilean Andes. This allowed them to observe the gases 2I/Borisov released as it moved closer to our Sun, thus providing the first-ever chemical composition readings of an interstellar object.

Continue reading “Interstellar Comet 2I/Borisov Formed in a Very Cold Environment”

When Comets Break Up, the Fragments Can Be Devastating If They Hit the Earth

Comet breakups are a timely topic right now. The interstellar comet 2I/Borisov just broke into at least two pieces. And though that comet is speeding out of the Solar System, never to be seen again, most of them don’t leave the Solar System. Most of them orbit the Sun, and return to the inner Solar System again and again.

A new paper examines the potential hazard to Earth from comets that break into pieces. The author makes the case that comet breakups could have had a hand in shaping the ebb and flow of life on Earth. It could happen again.

Continue reading “When Comets Break Up, the Fragments Can Be Devastating If They Hit the Earth”

Interstellar Comet 2I/Borisov Appears to Have Broken in Half

In 2019, amateur astronomer Gennadiy Borisov discovered a comet, which now bears his name. There’s a long history of amateur astronomers discovering comets, as they approach our inner Solar System on their elongated orbits. But this one was different: it was moving much too fast to be gravitationally bound to the Sun.

It was an interstellar comet. And now, it looks like it has split into two chunks.

Continue reading “Interstellar Comet 2I/Borisov Appears to Have Broken in Half”

Rosetta Saw the Building Blocks of Life on Comet 67P

Why is there so little nitrogen in Comet 67P/Churyumov-Gerasimenko (67P)? That’s a question scientists asked themselves when they looked at the data from the ESA’s Rosetta spacecraft. In fact, it’s a question they ask themselves every time they measure the gases in a comet’s coma. When Rosetta visited the comet in 2014, it measured the gases and found that there was very little nitrogen.

In two new papers published in Nature Astronomy, researchers suggest that the nitrogen isn’t really missing at all, it’s just hidden in the building blocks of life.

Continue reading “Rosetta Saw the Building Blocks of Life on Comet 67P”

NASA’s TESS Watched an Outburst from Comet 46P/Wirtanen

TESS, the Transiting Exoplanet Survey Satellite, has imaged an outburst from the comet 46P/Wirtanen. It caught the outburst in what NASA is calling the clearest images yet of a comet outburst from start to finish. A comet outburst is a significant but temporary increase in the comet’s activity, outside of the normal sunlight-driven vaporization of ices that creates a comet’s coma and tail.

Astronomers aren’t certain what causes them, but a new study based on this observation is shedding some light on them.

Continue reading “NASA’s TESS Watched an Outburst from Comet 46P/Wirtanen”

Interstellar Comet Borisov is About to Make its Closest Approach to Earth

On August 30th, 2019, astronomers with NASA, the ESA, and the International Scientific Optical Network (ISON) announced the detection of the interstellar comet C/2019 Q4 (2I/Borisov). News of the object was met with a great deal of excitement since it was only the second interstellar object to be detected by astronomers – the first being the mysterious object known as ‘Oumuamua (which astronomers are still unsure about)!

After a lot of waiting and several follow-up observations, 2I/Borisov is about to make its closest approach to Earth. To mark the occasion, a team of astronomers and physicists from Yale University captured a close-up image of the comet that is the clearest yet! This image shows the comet forming a tail as it gets closer to the Sun and even allowed astronomers to measure how long it has grown.

Continue reading “Interstellar Comet Borisov is About to Make its Closest Approach to Earth”

Comets and Interstellar Objects Could be Exporting Earth Life Out into the Milky Way

For over a century, proponents of Panspermia have argued that life is distributed throughout our galaxy by comets, asteroids, space dust, and planetoids. But in recent years, scientists have argued that this type of distribution may go beyond star systems and be intergalactic in scale. Some have even proposed intriguing new mechanisms for how this distribution could take place.

For instance, it is generally argued that meteorite and asteroid impacts are responsible for kicking up the material that would transport microbes to other planets. However, in a recent study, two Harvard astronomers examine the challenges that this would present and suggest another means – Earth-grazing objects that collect microbes from our atmosphere and then get flung into deep-space.

Continue reading “Comets and Interstellar Objects Could be Exporting Earth Life Out into the Milky Way”