by Kim Malville
This is the month for lovers of Venus. The brilliant planet rises higher and higher in the evening throughout the month. Its altitude at sunset increases from 16 ° to 22 °, getting brighter every night. Venus is bright because of its cloud cover, but below it lies the hottest planet in the solar system, with a temperature of 863° F. Its dry, desiccated surface, once possessing oceans and lakes of water, has been destroyed by climate change brought on by carbon dioxide in its atmosphere. Beware you Earthlings!
At the first of the month Saturn is easy to find to the right of Venus, but it gets lost in the light of the setting sun at the end of the month. Mars is still visible in November, appearing about due south as the sun sets.
November 1-3: Look for the young crescent moon as it travels past Venus and Saturn some 45 minutes after sunset. On November 2 it will lie exactly above Saturn.
November 14: Full moon. The moon is closest to the earth than at any time between 1976 and 2020.
Don’t cry for me, Earth
On September 30 the Rosetta, the comet orbiter, finished its nearly 26-month visit to comet 67P by touching down on the surface of the comet and turning itself off.
After more than 10 years in space, Rosetta arrived at 67P on August 6, 2014.Three months later, a lander named Philae detached from the orbiter and dropped to the comet’s surface. It didn’t go as planned. Philae was not able to attach itself to the surface by harpoons as planned, by bouncing twice and ending up in the shadow of a cliff.
Without the sunlight to charge its battery, Philae went to sleep about 60 hours later. Unlike Philae, the orbiter was never designed to land on the comet. Despite gently coming to rest at a speed of less than two miles per hour, parts of it probably broke apart. We’ll never know the details, as it is now dead silent.
As you perhaps remember, Comet 67P is famous for its oddball shape. With two lobes joined together at a neck, it resembles an interplanetary dumbbell or a peculiar peanut. Rosetta photographed a large crack in its neck in 2014. After the comet made its closest approach to the sun in August 2015, the crack grew by several hundred meters and new cracks appeared.
The fractures appear to be developing as forces bend the comet back and forth, becoming strongest when it comes closest to the sun: a true pain in the neck of astronomical proportions! Apparently the ends bend in opposite directions as the comet spins, flexing the neck and creating stress. Because the comet isn’t held together very strongly, with the body strength of a snowball, the neck is starting to break. At this rate, in a few hundred years, the comet could fold itself in half as the two lobes snap apart and meld together. Rarely in astronomy do we find changes that occur so quickly.
Would Pluto by any other name smell as sweet?
Planet Nine, the replacement of Pluto, has a good chance of lurking unseen in the dark depths of the outer solar system. Its days of hiding may be numbered. The evidence for Planet Nine’s existence has continued to grow over the past nine months, as several different research teams have determined that the orbits of other small, distant objects appear to have been influenced by its presence. This hypothetical giant planet (Pluto is only a dwarf) is thought to be about 10 times more massive than Earth, taking some 20,000 years to orbit the sun. It will be discovered within 16 months or so, as predicted by Mike Brown, the astronomer who killed Pluto. Brown said that 8 to 10 groups are currently looking for the planet.
The latest evidence for Planet Nine comes from a peculiar aspect of the solar system. The plane in which the eight major planets orbit the sun is tilted from the sun’s equator by six degrees. The best explanation for that tilt is that the gravitational influence of a distant large planet has slowly, over the past 4.5 billion years, pushed the other planets out of their original orbits. Not a bad replacement for the original dwarf. Pluto lovers should be pleased, although we can be sure that Planet Nine, when actually discovered, will be named Pluto. The search is on! This is an exciting hunt to be watching from the bleachers.
Studies of Mars’ moon Phobos has a connection with keeping the Earth safe from asteroids, the Lawrence Livermore National Laboratory (LLNL) announced recently.
Phobos has a huge crater, more than five miles across, and a new computer model by the LLNL in California simulates the dramatic impact that could have caused that distinctive crater. The research is part of a planetary defense program, studying how to protect Earth from a devastating impact.
Those studies have demonstrated that a crater of this size can be created without destroying the moon, which actually used to be an asteroid. The object that slammed into Phobos and created what’s called the Stickney Crater could have been about 820 feet across and been traveling at a speed of about 13,420 mph. It did not shatter the asteroid, and if something like it were moving toward Earth, a powerful nudge such as this would have diverted it from impacting our planet. That could involve ramming a spacecraft into the asteroid to change its course, or even detonating a nuclear device near it. A nuclear explosion near the asteroid would heat up one part of it, and acting like a rocket engine, could propel it on a safe course, taking Earth out of the crosshairs. This would work for an asteroid like Phobos, but probably not for a fragile object like Rosetta’s Comet which could split and shower the earth with many fragments. We should be afraid, be very afraid, of throwing nuclear devices around the solar system!