Travelers In The Night

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 visible in asteroid hunter's telescopes for about 16 days, as it streaked across our planet's orbit at 37 miles per second, as it continued to move away from the Sun. During that brief period of time it was discovered by the PanSTARRS group in Hawaii, tracked by telescopes around the world, and given the name Oumuamua (“Oh-moo-ah-moo-ah”). Turns out that previous to the discovery observations, sightings too sparse to report, were obtained by my team using the Catalina Sky Survey's Schmidt telescope on Mt. Bigelow, Arizona. In 2024 this unusual space rock will cross Pluto's average distance from the Sun traveling on a path which will take it into deep interstellar space. Since we don't know how Oumuamua could obtained it's current trajectory from processes in our solar system, it is safe to presume that it originated in truly deep space. The mystery of Oumuamua deepened when astronomers measured it's brightness to change regularly by nearly 10 times over a 7.3 hour period of time. If these brightness variations are due to it's shape, and thus the amount of sun light reflected as it rotates, Oumuamua looks like a cigar. Even though Elon Musk's SpaceX Mars rocket could catch Oumuamua, it is more cost effective is to simply wait to discover another one of the several interstellar asteroids which pass by us each year.

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 happened over the past 100 years. Restoring the natural night sky is relatively simple and can even save money. Before restoration can effectively begin it is essential to make night sky brightness measurements in both natural night sky and urban locations.

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 and reported their observations to the American Meteor Society. The one which exploded over Arizona was probably several feet in diameter and entered the Earth's atmosphere over Flagstaff. This event was observed in Arizona, California, Nevada, Utah, New Mexico, and Colorado. It was recorded by numerous electronic security and dashboard cameras and was visible for from 3 to 7 seconds. This meteor also produced a booming sound which was reported by about a dozen different observers. The fireball was last seen over Happy Jack, Arizona and is likely to have produced meteorite fragments which are scattered along Interstate 17 somewhere in the rugged country between Phoenix and Flagstaff. There are likely to be on the order of 1,000 fireball events over the Earth every day. Most of them occur over the oceans or during the day and pass unobserved by humans. During the first 10 months of 2017 the most energetic fireball event occurred when a meteoroid entered the Earth's atmosphere at 8.5 miles/second above the ocean between Australia and Antartica. If you record a fireball with your dash cam or security camera report it to the American Meteor Society. Your data will be very important in finding out where it came from in the solar system as well as to indicate where it might be possible to find pieces of it on the ground.

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 destruction as well as global disruption of agriculture and other human activities. This goal has been accomplished. In 2005 Congress extended the mandate to require NASA to detect and track 90% of the 140-m asteroids capable of destroying a large metropolitan area.

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 out to have the nasty habit of emitting bursts of radiation which are likely to sterilize and/or remove the atmospheres of it's family of planets. Recently, hope of finding a nearby Earth was rekindled when scientists at the European Southern observatory in Chile discovered a small planet circling what appears to be a quiet well behaved red dwarf star 11 light years from us. Astronomers are not yet sure that this newly discovered Earth sized planet lies within it's stars habitable zone where liquid water could exist on it's surface. Jumping the gun, ET enthusiasts have beamed a friendly message in the direction of another nearby red dwarf planet system. Their target the super Earth planet, GJ 273b is located some 12.4 light years away near the bright star Sirius in the constellation of Canis Major. At this distance a civilization on GJ 273b could have already received a picture of humanity by deciphering 'I love Lucy' and other TV signals it has been picking up for 50 years or so. The next generation of very large telescopes will allow astronomers to search for the presence of oxygen and other molecules which indicate the presence of life in the atmospheres of nearby worlds. In the mean time we have more reasons to be thankful for what we have here on planet Earth. For Travelers in the Night this is Dr. Al Grauer. Go to travelersinthenight.org program 417 for more information.