Another Visitor from Beyond: C/2019 Q4 (Borisov)

Boy, this has been an intense week for astronomy news. First there was the largest neutron star ever discovered (it would take an eighth grader nearly an hour to bicycle a distance equivalent to its diameter!), then there was the story about Tabby’s Star gulping down exoplanets and pulverizing a moon (Ferrebeekeeper didn’t post that one, but you can read about it here) and now, today brings reports of another extra-solar mystery object akin to the mysterious Oumuamua which caused such a sensation back in 2017.

C/2019 Q4 (Borisov) in the middle of the image: Note the faint tail!

Back in August 30, 2019, Gennady Borisov, an amateur astronomer from Ukraine, spotted an unknown comet which has been dubbed “C/2019 Q4 (Borisov)”.  Not only is the comet traveling at the blazing speed of  150,000 kilometers per hour (93,000 mph), it also has a hyperbolic orbit (meaning the object is not bound to the solar system) and it is approaching from a strange angle which in skew to the planar disk of the solar system.

At present the comet is far away from Earth and yet approaching on a path which puts the sun between us and the object (astronomers don’t like pointing their telescopes into the sun for some reason), however the mysterious object should approach as close as Mars at which point we will be able to learn more about it.  Right now all we know is that C/2019 Q4 (Borisov) has a diameter between 2.4 and 15 kilometers (1.5 to 10 miles) and doesn’t seem to be from around here.  Whereas Oumuamua zipped through before we could get a good handle on it, we should have a chance to properly study this comet. Since comets (unlike strange asteroid shards) are volatile, we should be able to get a sense of its composition by studying the makeup of the tail.  Stay tuned for more news about this peculiar object!

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New Planets!

Exciting news from the heavens!  Today NASA has reported that the Kepler mission has discovered 3 new planets in the habitable zones of two distant stars.  Of the thousands of worlds so far discovered, these three are most likely to be habitable.  Best of all the planets are crazy!

Kepler is a NASA space telescope which was launched on March, 2009.  It makes use of an incredibly sensitive photometer to simultaneously & incessantly monitor the brightness of over 150,000 nearby stars.  The brightness of a star dims slightly whenever an exoplanet transits between it and Kepler.  Thanks to Kepler’s inhuman vigilance and robotic ability to perceive nearly imperceptible light changes, we are now discovering thousands of new planets, although most of them are Jovian sized gas worlds.

Kepler Space Telescope

The three worlds reported today lie in the habitable zone—the region around a star where water exists in a liquid form (as it does here on beautiful Earth).  Two of the newly discovered habitable zone planets are in a five planet system orbiting a dwarf star just two-thirds the size of the sun which lies 1,200 light years from Earth.   Here is a diagram of the Kepler 62 system.

Kepler 62 System (Art by NASA)

Of these five worlds, two lie in the habitable zone, Kepler 62f and Kepler 62e.  Kepler 62 F is most likely a rocky planet and is only 40 percent larger than Earth.  It has an orbit which last 267 (Earth) days.  So far it is the smallest exoplanet found in the habitable zone.  The star it orbits is 7 billion years old (as opposed to the sun which is four and a half billion years old) so life would have had plenty of time to develop.  The other habitable zone planet in the Kepler 62 system, Kepler 62e is probably about 60% larger than our planet.   It is somewhat closer to the star and astrophysicists speculate it may be a water world of deep oceans.

No! Not that sort of Waterworld!

The other new exoplanet Kepler-69c appears to orbit a star very similar to Earth’s sun.  It orbits at the inward edge of the habitable zone (nearing where Venus is in our solar system) so it may be hot.  The planet is estimated to be about 70% larger than Earth, and is also thought to be a water world with oceans thousands of kilometers deep.  I am finding it impossible not to imagine those vast oceans filled with asbestos shelled sea-turtles the size of dump trucks, huge shoals of thermophile micro-squid, and burning-hot chartreuse uber-penguins, but if any life is actually on Kepler-69c, it is probably extremely different from Earth life.

I understand why they are green and have gills, but why are they inside gelatin capsules? (DC Comics)

Of course Kepler can only find these planets; it is unable to observe very much about them.  In order to do that, humankind will need some sort of huge amazing super telescope.  Speaking of which, tune in next week when I write about humankind’s plans for building a huge amazing super telescope in the Chilean Andes!