The August Skies
Mercury is behind the sun in relation to Earth and is not visible this month.
Venus shines brilliantly in the morning twilight during August. Look for it low in the east-northeast predawn sky. On August 18th, the two brightest planets, Venus and Jupiter, will be very close together before sunrise. Jupiter will then move farther away from Venus each morning throughout the rest of the month.
Mars can be spotted low in the west-southwest evening twilight, sinking lower each night during August. Saturn approaches close to Mars during the last week of the month.
Giant Jupiter appears low in the east-northeast predawn sky during the second week of August. It then rises higher in the sky each morning. On the morning of Aug. 18, don’t miss the close conjunction of Jupiter and Venus.
Beautiful Saturn appears in the west-southwest evening twilight as the sky darkens. It will sink lower in the sky each night during the month.
Watch the Perseids Meteor Shower on the night of Aug. 12-13. A waning gibbous moon will drown out the very faint meteors but the brighter ones should produce a good show. Observe from a dark site between midnight and dawn.
“The important thing is not to stop questioning.”
– Albert Einstein (1879-1955)
Although I have had in interest in astronomy since junior high school, I am amazed at times at the high level of interest that exists in the general population. Because of the incredible boom in technology, amateurs now possess equipment that was available only to professional astronomers just a few years ago. Amateurs can now peer many millions of light years into deep space to observe and image objects that lie in the remote regions of intergalactic space.
Over the past 23 years, thousands of people, mostly students, have visited my observatory. Now, requests for tours of the facility are referred to the Martz Observatory, where a much larger facility offers a more comfortable experience. One of the things I will miss most is the multitude of interesting questions asked by the visitors over the years. Some of the questions that come to mind are:
What colors are the planets? Because Mercury has almost no atmosphere, we see just its gray rocky surface. Venus has a thick atmosphere composed of sulfuric acid clouds and it appears a bright white-yellowish color in a telescope. Earth from space is a prevailing blue color. With very little atmosphere, Mars appears reddish-orange due to the rusty rocks on its surface. Jupiter is covered by enormous orange and white cloud bands. Saturn is a pale, creamy yellow color. The methane clouds that cover Uranus and Neptune give both of these planets a light blue color.
Which planets have rings? The four giant planets, Jupiter, Saturn, Uranus and Neptune, all have rings. Jupiter has four main rings, Saturn has 12, Uranus has 13 and Neptune has 6.
How big is the Earth compared to the sun? Since the sun’s radius is a little over 100 times that of Earth, over one million Earths would fit inside the volume of the sun.
What is the biggest galaxy? One of the largest known galaxies is located in the center of a distant galaxy cluster named “Abell 2029.” It lies about one billion light-years away and is approximately 60 times larger than our Milky Way Galaxy. Astronomers estimate that its elliptical shape contains at least 100 trillion stars.
Is everything we see in space moving? Yes, every single thing we can detect in space is moving, some at tremendous speeds. Distant galaxies appear to be rushing away from us. The further away from us they are, the faster they are moving. This is due to the expansion of space itself and this expansion is carrying the galaxies with it. Our Milky Way Galaxy, containing at least 300 billion stars, is hurtling through space at 324 miles per second toward the constellation Hydra. Our galaxy is a member of a large cluster of galaxies and the entire cluster is speeding in the direction of the constellation Virgo.
What happens when galaxies collide? Since many galaxies are members of large groups or clusters, collisions between them are unavoidable. Using modern telescopes, astronomers have detected many galaxies in various stages of collision. Because there are many billions of stars in most galaxies, one would think that during galaxy collisions, most stars would collide and destroy each other. However, the spaces between the stars are so enormous (the nearest star to our sun is 24 trillion miles away) that actual star collisions are rare. In fact, the incredible gravitational shock waves created during galaxy collisions create bursts of new star formation, resulting in massive star creation rather than destruction.
If discovered some day, what will alien life on other worlds be like? Because the human mind can hardly conceive the vast number of worlds in the universe, there are undoubtedly other types of life out there somewhere. Most likely, any alien life that is discovered on other worlds will be simple lifeforms such as bacteria or viruses. There is practically no chance that any alien life will resemble humans since we evolved over billions of years and have adapted uniquely to Earth’s environment.
Is it true that you can buy a star? No, a person cannot purchase a star and officially put their name or the name of a friend on it. The International Astronomical Union is the only worldwide organization that can officially name natural objects in outer space. Unfortunately, there are companies that operate huge scams, taking money from people in exchange for bogus certificates that state the purchaser owns a star located at a certain point in the sky. In many cases, the designated star is even too dim to be visible without a telescope. It’s much better to go out on a clear night and pick out a nice, bright star and make it your star.
When did Galileo invent the telescope? He didn’t. The telescope was actually invented by a gentleman named Hans Lippershey in Holland in 1608. Galileo was the first person to use the telescope to observe objects in the night sky such as the moon, Venus, Jupiter, and Saturn.
Will the moon ever collide with the Earth? Probably not. The moon is actually slowly drifting away from Earth at a speed of about 1.5 inches every year. In a billion years or so, the moon will appear smaller than the sun and total solar eclipses as seen from Earth will no longer be possible.
How cold is it in deep space? The temperature in deep space, with nothing else around, is slightly above absolute zero. The Cosmic Microwave Background (CMB) radiation, which permeates everywhere in the entire universe, keeps the temperature in deep space 2.73 degrees above absolute zero. This CMB is residual radiation left over from early in the development of the universe, soon after the Big Bang. Although initially it was a white-hot mist of hydrogen plasma, it has cooled over billions of years as the universe expanded, to its present -459.67 degrees F.
Why is it called the “Hubble Space Telescope?” It was named in honor of the famous astronomer Edwin Hubble, who solved two very important questions in astronomy. He discovered that spiral nebulae, thought to be located in our Milky Way Galaxy, were really other galaxies in distant regions of space. He then went on to show that these remote galaxies were receding from us at speeds proportional to their distances away from us.
Editor’s note: This monthly guide to the stars is from the Marshall Martz Memorial Astronomical Association and The Post -Journal. For further information, contact the M.M.M.A.A. at www.martzobservatory.org.