Travelers In The Night

Most small asteroids are likely to be rubble piles of small rocks and dust loosely held together by their weak force of gravity while others may be made of ices of various substances. A few are solid objects which may contain metals like iron and nickel as well as gold, silver, and platinum. As they whiz by us it is hard to tell much about them from their overall brightness and distance from us. In 2017 my team the Catalina Sky Survey found 21 asteroids having an average diameter of 750 feet which pass closer to the Sun than the planet Mercury. They must be made of very tough rocky material since they regularly receive more solar energy than heats the surface of Mercury to 800F. Over the centuries this repeated baking has likely removed all of their water and other volatile materials leaving only rocky metallic minerals. The largest of this group of tough guys is the half mile in diameter asteroid 2017 VV14 which orbits the Sun once every 3.4 years and can come to about 20 times the Moon's distance from us. The smallest is the 30 foot diameter tiny asteroid 2017 RQ17 which orbits the Sun once every 214 days on a path that brings it close to Mercury, Venus, Earth, and Our Moon. Based on known terrestrial deposits many of the key elements required for modern industry and food production such as phosphorus, antimony, silver, gold, and copper could be exhausted on Earth in the next 50 to 60 years. Perhaps in the future humans will mine tough asteroids for the materials they need.

My team the Catalina Sky Survey has pioneered searching for asteroids coming from the direction of the dark side of the moon.

The beautiful star cluster the Pleiades in the constellation of Tauris is about 100 million years old making it one of the youngest objects that you can see in the natural night sky. Data obtained by observing Oumuamua (“Oh-moo-ah-moo-ah”), the first object humans have identified which is definitely from outside of our solar system suggests that it is an icy body with a red, rock appearing shell, of carbon rich organic material. By tracing Omuamua's path for millions of years into the past, Dr. Fabo Feng of the University of Hertfordshire , found that it's slow speed in the vicinity of 5 stars in the Pleiades suggests that it was ejected from one of them. Check out the Pleiades with your unaided eye, binoculars or a small telescope and contemplate the messengers it might be sending our way.

A start up company Reflect Orbital is proposing to launch 50,000 satellite mirrors by 2035 to illuminate solar panels on Earth all night long. This would be devastating for human sleep cycles, birds, insects, plants  and many of the biological systems of organisms on which we all depend.

The mysterious Earth approaching object Phaethon (FAY-eh-thon) does not fit neatly into our definition of either an asteroid or a comet. Further it appears to be like the Peanuts character Pigpen in that it leaves a trail of dust and other fine debris in it's wake which in the case of Phaethon produces the Geminid Meteor Shower to delight us every year around Christmas time. Phaethon is amazing in that every 524 days it makes a death defying flight to a point less than one of half of the planet Mercury's distance from the Sun, where it's surface temperature reaches a mind boggling 1,200 Fahrenheit. During one of these events the NASA Stereo Spacecraft A discovered that Phaethon had rock dust tail.