Asteroid hunters find asteroids by looking for objects which change their position relative to the stars.  If an asteroid happened to match the Earth’s motion it might appear stationary and thus be virtually undetectable until it is right on top of us. The trick is finding potentially dangerous asteroids at some other point in their orbit so we know about them before they have a chance to approach Earth.

Most of the humans on planet Earth have never witnessed that the natural night sky is not dark; but rather it is alive with it's own lights. To see for yourself, pick a dark sky place near you like the Cosmic Campground International Dark Sky Sanctuary from the International Dark Sky Association's website, darksky.org, and recruit a friend. Do a bit of research on how to achieve and sustain your night vision. Bring a red filtered flashlight, reclining lawn chair, star maps, binoculars, warm clothes, a telescope if you have one, and snacks. Keep on the look out for special events. The American Meteor Society's website will let you know when to expect meteor showers. Most humans have never seen the glowing light pyramid called the Zodiacal light which is produced by ice particles and dust in the solar system. In the northern hemisphere it is prominent in the evening sky in February, March and April. During the same months it lights up the predawn sky in the southern hemisphere. Star clusters scattered around the sky can be enjoyed with binoculars or a small telescope. New Moon's from May through October will provide you opportunities to explore the Milky Way with your naked eye or pair of binoculars. This adventure will fill you with wonder at what might be out there. Last but not least Mars will dominate the night sky during much of 2018 as it and the Earth come near to each other. For a time in late July of 2018 Mars will even outshine the giant planet Jupiter in the night sky.

My Catalina Sky Survey teammate Josh Hogan was asteroid hunting in the constellation of Ursa Major with our small but mighty Schmidt telescope when he spotted a fast moving point of light in a set of his images and posted his observations on the  Near Earth Object Confirmation Page or NEOCP for short. The NASA Sentry software system automatically scans the NEOCP and from the initial observations of Josh’s discovery predicted there was a tiny minuscule but non zero chance that it could impact our home planet in the next 100 years. Asteroid hunters were able to show that 2026 GB is not a threat only after they had accumulated enough data to accurately determine its orbit which demonstrates that planetary defense is by necessity an international effort.

On December 25, 2017, while searching for Earth approaching asteroids in the constellation of Virgo, the Universe gave my Catalina Sky Survey teammate Greg Leonard a Christmas present in the form of a comet which now bears his name. Comet P/2017 Y3 (Leonard) orbits the Sun once every 31 years on a highly elliptical path which takes it from between the orbits of Earth and Mars out to almost the planet Uranus's average distance from the Sun. Since it has been observed for only a very short piece of it's path about the Sun, it is not possible to accurately predict Comet Leonard's location very far into the future. In 2017 and 2018 it appeared as a faint fuzzy point of light in the night sky and never came came closer than about 150 million miles from Earth. Comet Leonard's next visit to our neighborhood will be in 2033 or 2034. At some point in the future it's orbit could bring much closer to Earth as it comes into the inner solar system about twice every human lifetime. Greg's comet is classified as a Halley family comet and although it is difficult to predict how a comet will brighten as it approaches the Sun, it is unlikely that it will ever become as bright as it's famous cousin. That situation could change when Comet Leonard comes near the giant planet Jupiter. In the past Jupiter has sent Comets in our direction or ejected them from the solar system. Only time will tell.
For Travelers in the Night this is Dr. Al Grauer.

The visually stunning Lunar Crater Pierazzo, named for the late Planetary Scientist Elizabeth “Betty” Pierazzo was observed by the Artemis II Crew as they passed over the Moon’s far side.  It is a 5.9 mile diameter crater with white streaks or rays which extend more than 50 miles in all directions.

Most asteroids are located in the lonely space between Mars and Jupiter where the average distance between two asteroids is about 600,000 miles. Even though there is a tremendous space between asteroids they occasionally collide and pieces of them become Earth approaching objects. Most of them remain close to the plane of the solar system, however, a few are sent on paths which take them into the extremely lonely space high above and far below the orbits of the planets about the Sun. In 2017, my team, the Catalina Sky Survey, discovered 13 of these loneliest asteroids whose paths are tilted more than 45 degrees to the plane of the solar system. They have an average diameter about 4 times larger than that of the 987 asteroids we discovered in 2017. Even though 13 is a small sample it is interesting to speculate what this size difference could mean. In 2013, astronomers used the Subaru Telescope on Mauna Kea in Hawaii to discover that main belt asteroids with orbits which are highly inclined to the plane of the solar system tend to be larger and made of stronger materials than those asteroids which reside in the plane of the solar system. They attribute these differences to the collisions which must have occurred to send asteroids into highly inclined orbits about the Sun. If this result applies to the lonely near Earth asteroids we discovered then perhaps they are made of very strong materials and could be of particular interest to asteroid miners.

My Catalina Sky Survey teammate Josh Hogan has discovered a 2 football field diameter asteroid that was placed on NASA’s Sentry list because it has a tiny minuscule but non-zero chance of impacting our home planet. With this motivation my team the Catalina Sky Survey, the Pan STARRS group in Hawaii,  the ATLAS group with telescopes Hawaii, Chile, and South Africa , the Vera C. Rubin telescope in Chile, will be soon joined NASA’s NEO Surveyor and groups world wide in a planet wide defense network.

Asteroids appear as moving points of light in an asteroid hunter's images so that when my Catalina Sky Survey teammate Alex Gibbs spotted a fuzzy moving object he immediately suspected it to be a comet. The data obtained by astronomers over the next 8 days enabled scientists at the Minor Planet Center to verify Alex's 31st comet discovery and give it the name C/2018 A6 (Gibbs). In January of 2018 it was in the constellation of Leo traveling from the vast empty space above the Sun's north pole toward the plane of the solar system which contains all of the planets and most of the asteroids. In March of 2018 Comet C/2018 A6 (Gibbs) will cross the plane of the solar system a bit farther from the Sun than the giant planet Jupiter's orbit. After that it will continue on a wide arcing parabolic path, pass under the Sun's south pole in the summer of 2019, and once again cross the plane of the solar system in February of 2021. After that it will continue into the vast empty space above the Sun's north pole from whence it came. How a comet brightens as it approaches the Sun is difficult to predict. With luck humans will be able to spot Comet C/2018 A6 (Gibbs) with their naked eye, binoculars, or a small telescope as it pays a rare visit to our planet's neighborhood.

On St. Patrick’s day 2026 a fireball meteor brighter than the full moon streaked across the daytime sky.  The American Meteor Society received 223 eyewitness reports from observers in 15 states, the District of Columbia, and Ontario Canada as well as 5 videos and 6 photos.  NASA reported that the incoming object was approximately 6 feet in diameter, weighed about 7 tons, released the energy of 250 tons of TNT, created a sonic boom heard over a wide area , and rained bits of itself onto the ground in Medina county Ohio.

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.