Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps.  581 & 582: Planet Hunting & Stealthy Asteroid

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s 2 topics:

  •  The hunt is on for Earth like planets which are close enough for us to study in detail. Like TOI 700 d…
  • Carson Fuls discovered 1,000’ diameter PHA 2020 CL1.

Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona.  This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.

He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.

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581: Planet Hunting

The hunt is on for Earth like planets which are close enough for us to study in detail. The NASA Transiting Exoplanet Survey Satellite, or TESS for short, is observing nearby stars looking for planet revealing dips in brightness,  which occur when a planet passes between its star and our line of sight. TESS has been joined by the European Space Agency’s Cheops Satellite whose job is to characterize exoplanets known to be orbiting nearby bright stars. Together these two satellites promise to bring us knowledge of nearby Earth like worlds. Recently TESS discovered a planet, now named TOI 700 d , orbiting a red dwarf star in the constellation of Dorado about 100 light years away. This discovery has been verified NASA’s Spitzer Space Telescope.

The new planet TOI 700 d has about twice Earth’s mass, is about 20% larger than Earth, and orbits its star once every 37 days. TOI 700 d obtains about 86% of the energy Earth receives from our Sun and is likely to have a surface temperature at which liquid water could exist.  TOI 700 d is likely to be tidally locked in the sense that one side of it has continuous daylight and the other side has perpetual night.  By studying the pattern of colors in a planet’s atmosphere which are present and missing scientists are able to characterize an exoplanet’s atmosphere. This measurement for TOI 700 d will be difficult but perhaps possible using NASA’s James Webb Space Telescope which is scheduled to be launched in 2021 and/or one of the new generation of huge telescopes now under construction. 

582: Stealthy Asteroid

Asteroids which approach Earth from inside of our orbit about the Sun are often difficult to discover and may represent a unique threat to our home planet.  My Catalina Sky Survey teammate Carson Fuls discovered one of these stealthy asteroids with our Schmidt telescope on Mt. Bigelow  AZ as it streaked through the constellation of Libra at 13 miles/second.  After Carson posted his observations on the Near Earth Object Confirmation web page his discovery was tracked by observers around the world.  

Scientists at the Minor Planet Center used these observations to estimate it to be 1,000 feet in diameter, calculate its orbit about the Sun, and give it the name 2020 CL1.  2020 CL1 spends most of its time inside the Earth’s orbit about the Sun on a path that is tipped at 45 degrees to that of the planets and most of the rest of the asteroids in our solar system.  On its journey it crosses the orbits of Mercury, Venus, and Earth.  2020 CL1 is classified as a potentially hazardous asteroid because of its size and that it can come to 4.4 times the Moon’s distance from us.

According to the Purdue University and Imperial College of London’s impact calculator an asteroid the size of 2020 CL1 enters the Earth’s atmosphere about once every 67,000 years and could create a crater 2.8 miles in diameter and 1,500 feet deep in sedimentary rock.  If you were 50 miles from the point of impact you would feel the effects of a 6.7 magnitude Earth quake. Fortunately 2020 CL1 will not strike the Earth in the foreseeable future.

For Travelers in the Night this is Dr. Al Grauer.

End of podcast:

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