393E-431-Tough Space Rocks

393E-431-Tough Space Rocks

Author: Albert D. Grauer June 16, 2026 Duration: 2:01
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.

Each episode of Travelers In The Night feels like a quiet, personal conversation under a dark sky. Hosted by astronomer Dr. Albert D. Grauer, this podcast brings the distant cosmos into sharp, intimate focus. Dr. Grauer isn't just an observer; he's an active participant in the hunt, working with the Catalina Sky Survey team that has consistently discovered near-Earth asteroids for years. In these brief and engaging segments, you'll hear firsthand accounts of what it's like to track these ancient celestial travelers-the asteroids and comets that silently pass by our world. The discussions move beyond simple facts to explore the real-world implications of these discoveries, from planetary defense to the sheer wonder of our dynamic solar system. Accompanied by the contemplative music of John Lyell's "Eternity," each installment offers a moment of calm reflection on humanity's place in the universe. It’s a perfect blend of grounded science and cosmic curiosity, making complex astronomical concepts accessible and deeply fascinating. For anyone who has ever looked up and wondered what's out there moving in the dark, this podcast provides a direct line to the front lines of discovery.
Author: Language: English Episodes: 50

Travelers In The Night
Podcast Episodes
385E-421-New Aten [not-audio_url] [/not-audio_url]

Duration: 2:01
Recently my Catalina Sky Survey teammates Carson Fuls and Greg Lenoard discovered an Aten asteroid which orbits the Sun once every 272 days and on a path that crosses the orbits of Venus and Earth a number of times each…
895-Tracking Space Junk [not-audio_url] [/not-audio_url]

Duration: 2:01
According to NASA an average of one catalogued piece of space junk per day has come down to Earth over the past 50 years. Research is described which can track space junk in the atmosphere and provide the starting locati…
384E-420-Dry Sands [not-audio_url] [/not-audio_url]

Duration: 2:01
The NASA Curiosity Rover has shown us evidence of ancient rivers and bodies of liquid water on the martian surface. Given it's thin cold atmosphere, seeps of liquid water, presently on the surface of Mars which are capab…
894-Discovery Night at the Schmidt [not-audio_url] [/not-audio_url]

Duration: 2:01
On a recent night my Catalina Sky Survey teammate Vivian Carvajal found 4 Earth approaching space rocks with our small but mighty Schmidt telescope on Mt. Bigelow, Arizona. These Earth approaching asteroids are all small…
383E-419-ET's Cigar [not-audio_url] [/not-audio_url]

Duration: 2:01
In 2012 as it crossed the orbit of Neptune heading towards the Sun a small space rock was 250 times fainter than can be detected by the Hubble Space Telescope. Five years later, after it had rounded the Sun, it became vi…
893-DarkSky Oregon [not-audio_url] [/not-audio_url]

Duration: 2:01
Artificial light at night also known as light pollution is degrading human safety and health as well as damaging the natural environment on which we all depend. The loss of the connection with the natural night sky has h…
382E-418-Fireball II [not-audio_url] [/not-audio_url]

Duration: 2:01
Recently there were four fireball meteors, brighter than the planet Venus, which exploded over Germany, France, Ohio, and Arizona within the space of only 10 hours. A total of 1320 individuals were treated to light shows…
892-140m-asteroids [not-audio_url] [/not-audio_url]

Duration: 2:01
Humans can mitigate the damage done by the impact of an asteroid given a sufficient lead time. In 1998, the US Congress mandated NASA to detect and track 90% of the 1 km sized asteroids capable of effecting local mass de…
381E-417-Red Dwarf Planets [not-audio_url] [/not-audio_url]

Duration: 2:01
Astronomers continue to be delighted when they discover an Earth sized planet. Scientists were thus very disappointed when the red dwarf star hosting the nearest such planet, Proxima b some 4.2 light years away, turns ou…