Travelers In The Night

The orbits of the planets are closely aligned with the extension of the Sun's equator into space and are contained within the flattened disk of material which forms the plane solar system. Most asteroids have orbits with inclinations or tilts to the solar system's plane which are less than 20 degrees. Thus, when my Catalina Sky Survey teammate Rose Matheny discovered a small space rock which soars into the lonely space high above and below our solar system's plane, it got our attention. As with all of our asteroid discoveries, Rose had no idea of what kind of object she had discovered with our Schmidt Telescope on Mt. Bigelow, Arizona until it had been tracked by observers around the world. The Minor Planet Center used the data from 14 different telescopes to calculate an orbit, estimate a size, and give the new object the name, 2017 TF4. Rose's odd ball near Earth Apollo asteroid discovery , 2017 TF4, has an orbit which is tilted by 60 degrees to the plane of our solar system. It's inclination or tilt is greater than 99.5% of the other 8,000 known Earth approaching Apollo asteroids. 2017 TF4, Rose's 260 foot diameter discovery orbits the Sun at about the same distance as the Earth once every 414 days. Perhaps as asteroid hunters discover additional small objects with orbits similar to Rose's discovery we will be able to trace them back to when they were created by a catastrophic collision long ago.

Astronomers using the 8.1 m Gemini South Telescope in Chile were excited by the fact that 467P (LINEAR-Grauer)’s Centaur like orbit had been changed as the nucleus emitted rocket like bursts of gases as it was warmed by the Sun. Inert inactive asteroids orbit the Sun following the law of gravity whereas active asteroids can emit little rocket like bursts of gas which can change their path about the Sun in interesting ways. It is important to study objects like 467P (LINEAR-Grauer) to make sure their path about the Sun doesn’t change to make them a threat to our home planet.

Once every 1,435 days , a 780 foot diameter space rock that my Catalina Sky Survey teammate Carson Fuls discovered makes an annihilation defying close approach to our star. At it's nearest point to the Sun, Carson's well done space rock is traveling at an amazing 93 miles per second and receives 26 times the amount of solar radiation that heats the surface of the planet Mercury to 800F. After Carson first discovered his heat resistant space rock traveling towards it's next hot date with the Sun, it was observed by telescopes in New Mexico, Arizona, Hawaii, and England. These data allowed scientists at the Minor Planet Center to calculate it's orbit around the Sun, estimate it's size, and give it the name 2017 TC1. 2017 TC1 crosses the orbits of Mars, Earth, Venus, and Mercury and can come relatively close to Jupiter on it's extremely elliptical orbit about the Sun. It is possible that in the very distant past the giant planet Jupiter's pull on 2017 TC1 sent it on it's current path around the Sun. In September of 2021, 2017 TC1 will once again be bright enough for asteroid hunters to track as it makes another close approach to our Sun. At this time astronomers with be able to measure the pattern of colors that 2017 TC1 reflects which will reveal it's surface chemical composition. Until then we are left to wonder how it is possible for a space rock to survive on such a harrowing path.

In 1892 the world’s largest telescope, the Lick Observatory’s 36 inch refracting telescope made the news when E.E. Barnard discovered, Amalthea, the 5th moon of Jupiter. In 2025 this historic telescope made the news again when on Christmas morning winds of 114 mph blew off a 3 ton piece of the shutter on its dome.The adaptive optics research pioneered at Lick Observatory helped in the creation of the twin giant 10 meter telescopes that sit atop Mauna Kea in Hawaii.

Without additional data, the true nature of the rapidly northward moving point of light my Catalina Sky Survey teammate Carson Fuls had just discovered would have remained a mystery. Fortunately, this new object was tracked by telescopes in both Arizona and New Mexico. These data were used to calculate it's orbit around the Sun, estimate it's size, and give it the name 2017 UX5. When Carson first spotted this enormous 1,200 foot diameter space rock it was more than 30 million miles away traveling in our direction at 10.7 mi/s. It's orbit and that of the Earth's nearly intersect and at the closest point they are about two and one half times the Moon's distance from us apart. An asteroid the size of 2017 UX5 impacts the Earth every 76,000 years or so. According to the impact calculator developed at Purdue University and the Imperial College of London if 2017 UK5 is made of porous rock and came in at an angle of 45 degrees, it would start to break into pieces at an altitude of 41 miles and upon reaching the surface would create a crater 2.2 miles in diameter and 5/8 of a mile deep in sedimentary rock. The results 20 miles away from impact would be that of a 6.4 Richter Scale magnitude Earth quake followed by 176 mph air wind blast which would blow down 90% of the trees and collapse wood frame buildings. Fortunately asteroid hunters have not discovered any object like Carson's discovery with our number on it.