393E-431-Tough Space Rocks

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.

Denne episoden er hentet fra en åpen RSS-feed og er ikke publisert av Podme. Den kan derfor inneholde annonser.

Episoder(1000)

918-Auroras from Space

The northern lights or Aurora Borealis have fascinated humans throughout the ages. Today aurora watching is a multimillion dollar industry in places like Alaska, Canada, Norway, Sweden, Finland, Green...

25 Sep 2min

407E-448-Two PHA's

The large dangerous asteroids that we don't know about are what keep asteroid hunters going to the telescope.

22 Sep 2min

917-Space Dust

As the Earth orbits the Sun at 18.5 mi/s it sweeps up about 100 tons of micrometeorites and space dust every day of which some 14 tons eventually makes it to the ground. You can even find some of thes...

18 Sep 2min

406E-447-Nuking An Asteroid

Tonight, even though the chances are extremely slim, an asteroid hunter could find a sizable asteroid on a collision course with planet Earth. If we have decades warning, the potential impactor's arri...

15 Sep 2min

916-Past Glory

When accurately recorded historical observations do not agree with what we what we see today it is often very rewarding to find out why. In modern telescopes we see Theta Eridani to a be pair separate...

11 Sep 2min

405E-446-Asteroid Homestead

In the future one can envision a space mining family boarding a descendent of the SpaceX Falcon Heavy Launch Vehicle for a trip into low Earth orbit. A few hundred miles above the Earth's surface they...

8 Sep 2min

915-Raining Comets

The comets we observe generally start out as icy dirty snowballs of frozen gases like water and frozen carbon dioxide in the Oort cloud. If recent scientific analysis is correct, we are now witnessing...

4 Sep 2min