Travelers In The Night

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 separated by about 425 times our distance from the Sun orbiting a common center of gravity. Detailed observations of the spectrum of one of these show it to be itself a pair of stars orbiting each other every 4.1 days. One of this very close pair, as it is aging, dumps matter onto its companion causing it to brightened significantly. In the past this mass transfer rate was much higher than it is today and the naked eye brightness of Theta Eridani is fainter to us than it was long ago.

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 would rendezvous with their asteroid mining spacecraft which will be their home for the next five years or so.

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 a parade of comets produced by the passage of a star when our first ancestors began to roam the Earth in Africa.

A partnership of humans and computers will help to minimize the damage when asteroid hunters find a space rock with our number on it.

Looking into the sky at night with radio eyes you would not see the points of starlight forming the constellations instead you would see a very bright, colorful and wildly changing scene. In a desert valley near the Great Basin National Park Caltech is building the world’s largest radio telescope called the Deep Synoptic Array or DSA for short.

Although no comet nucleus impact on the Earth has been conclusively identified, there is some evidence that suggests the 1908 Tunguska event in Russia, which knocked down trees over a 770 square mile area, could have been caused by a fragment of Comet Encke. However there is no doubt that the Earth's collision with dust and small debris left trailing from comets produces some of the meteor showers we enjoy so much.

Bill Gray is an astronomer who specializes in tracking objects in space which come near the Earth. In addition to natural objects like asteroids and comets Bill also tracks rocket boosters and space junk that humans have discarded. On several occasions he has helped asteroid hunters to not waste time following a piece of space junk which initially appeared to be a threatening Earth approaching asteroid. Recently Bill used observations by very well equipped and talented amateur observers in Utah, England, China, and Mississippi to predict that the upper stage of a SpaceX Falcon 9 rocket will hit the Moon at 5,400 mph on August 5 of 2026.

In 2017 observers in 50 countries at 440 different observatories made nearly 19 million observations of asteroids and comets which enable scientists to calculate where about 800,000 objects will be in the future.

Recently on a Saturday afternoon a loud double booming sound startled residents of Massachusetts and Rhode Island as a large bolide meteor exploded high above. This type of space rock is a message from nature which reveals the conditions which existed when the planets formed.

During the only 3 clears hours of his first night solo as an asteroid hunter, my new Catalina Sky Survey teammate Brian Africano discovered two new Earth approaching asteroids with our Schmidt Telescope on Mt. Bigelow, Arizona. Since one of Brian's discoveries is almost 300 feet in diameter, astronomers at 18 different observatories around the world stayed on it for more than 68 hours, after Brian posted his discovery observations, to determine a reasonable orbit for it.

Comet 220P/McNaught orbits the Sun once every 5.5 years on a path which is between Mars and Jupiter. At that extreme distance, more than 1.5 times the Earth’s distance from the Sun, it still receives a significant amount of solar radiation. In 2026 Comet 220P/McNaught had an outburst which caused it to brighten 600 times in about 13 hours and then to continue to brighten to about 8,000 times brighter than in was in its pre-outburst state.

My Catalina Sky Survey teammate Carson Fuls was observing, in the constellation Lynx, with our Schmidt telescope on Mt. Bigelow, Arizona , when within the space of only 35 minutes, he discovered two small space rocks well before they made very close approaches to Earth. 79 hours after Carson discovered the first, 2018 CB, this approximately 70 foot diameter space rock passed about 1/5 of the Moon's distance from us. Turns out that the second of Carson's duo, an approximately 50 foot diameter space rock got near us first, when 62 hours after Carson discovered 2018 CC, it came to less than 1/2 of the Moon's distance from the surface of planet Earth. Since we didn't have a large enough, properly equipped telescope to measure the pattern of colors each of Carson's discoveries reflects from the Sun we can only estimate their physical sizes and guess at their densities and chemical compositions. In any event, if either of these space rocks were to strike the Earth they would likely explode at an altitude about 100,000 feet above the Earth's surface, releasing the energy of tens of thousands of pounds of TNT, producing a spectacular light show. Both of Carson's discoveries could be similar to the space rock which exploded over Chelyabinsk, Russia breaking windows, injuring nearly 1,500 people, and producing numerous fragments which made it to the ground. If either of Carson's discoveries had been on an impact trajectory with Earth, asteroid hunters would have had time to warn people in the effected area to stay away from doors and windows.

In an experiment that will involve all of the residents of planet Earth SpaceX has asked the FCC for permission to launch 1 million satellites into low Earth orbit to create a solar powered data center. Since the agriculture which produces our food is very sensitive to weather and climate it is important to conduct serious research about the effect of a mega constellation of satellites before allowing such a project to produce changes to the environment we don’t understand.

Elon Musk decided not to use a traditional mundane concrete block dummy payload for the first launch of the SpaceX Falcon Heavy launch vehicle to test his rockets lifting capabilities. After orbiting the Earth for 5 hours a third burn by the Falcon second stage placed a 2,750 pound payload consisting of a 2008 Tesla Roadster, Starman mannequin, Hot Wheels toy model roadster, electronic copy of Isaac Asimov's Foundation novels, and plaque etched with the names of more than 6,000 Space X employees into orbit around the Sun. Surrealistic video from a camera mounted ahead of this unusual spacecraft showed the red roadster and its dummy pilot with the Earth in the background. My Catalina Sky Survey teammate Greg Leonard joined with astronomers around the world in tracking starman and his booster rocket. The JPL Horizons Software system used 269 such ground-based optical astrometric observations spanning Feb 8 through 13 of 2018 to determine that Tesla and Starman will cross the orbit of Mars on July 31, 2018 and reach it's furthest distance from the Sun on November 9, 2018 before coming back to it's closest point about the Sun near the Earth's orbit on August 14, 2019. After that Starman and Tesla will continue to orbit the Sun for millions of years to come as a physical testament to human ingenuity and our sense of humor.

My Catalina Sky Survey teammates Josh Hogan and Alessandra Serrano were asteroid hunting in the constellation of Ursa Major when they discovered a fast moving point of light in the night sky. My team the Catalina Sky Survey operates 5 telescopes on top of mountains near Tucson, Arizona except for the 3 nights per month when the moon is too bright. Our goal is to detect an impacting object like 2026 JH2 in advance to warn people in the effected area to stay away from doors and windows.

Using our Schmidt telescope on Mt. Bigelow, Arizona, my Catalina Sky Survey teammate Richard Kowalski was searching for Earth approaching asteroids in the constellation of Virgo when he discovered a moving point of light which had suddenly appeared and was about 40 times brighter than is typical for a near Earth asteroid. 75 hours later, scientists at the Minor Planet Center used data from 17 different observatories around the globe to calculate it's orbit around the Sun, estimate it's size to be 630 feet in diameter, and give it the name 2018 BT6. Three weeks before Richard discovered 2018 BT6, it was very dim with less than 1% of it's illuminated side facing us as it came from the direction of the Sun giving humans little advance notice as it approached us at a speedy 16.4 mi/s. In 2018 this relatively large space rock came to about 18 times the Moon's distance from us. In the future it's orbit can bring it to about 0.6 of the Moon's distance from us. According to the Purdue University and Imperial College of London's impact calculator, one it's size impacts the Earth every 300,000 years or so creating a crater in sedimentary rock 7 miles in diameter and 2,000 feet deep. Fortunately 2018 BT6 will not strike the Earth in the foreseeable future, however, it's discovery presents us with the fact that currently humans would have little advance warning of the impact of a relatively large space rock if it approached us from the direction of our Sun.

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.