Introduction and Monthly Reminders
The first half of January brought cold temperatures and snow storms to the Salt Lake Valley in Utah. Typically, these storms seem to overlap with the best stargazing opportunities of the month. This was the case for the Quadrantid Meteor Shower, but I could see the Moon pass in front of and block Antares from view. Unfortunately, the clouds started to roll in, and I could not see this bright star emerge from the other side. Despite the storms, Jupiter and Saturn could still be seen during the clear evenings, and Venus could be seen with Orion in the cloud-free morning sky.
The next big stargazing event will occur shortly before sunrise on the 27th. On this date, a conjunction between Mercury and Mars will occur. Mercury should be easy to spot, but an optical aid such as a pair of binoculars or a telescope will be required to spot Mars. Aside from this rare conjunction, the Moon will pass close by each outer planet in turn, excluding Mars, from the 14th through the 19th. Comet Pons-Brooks may also be seen passing through Cygnus the Swan but will require binoculars or a telescope to spot. This comet is expected to brighten through April and may reach unaided-eye visibility. If an observer wants to spot Pons-Brooks now, use a stargazing app to find its precise location for the desired observation date.
My next solar system topic will be on Mars, the Red Planet. Mars is currently not at its best for observations from the Earth, but it is one of the most studied objects in the solar system and is the only planet to which NASA has sent rovers. Based on the information gleaned from these missions, it has been determined that Mars once had a warmer and wetter surface with a much thicker atmosphere. Scientists do not expect to find any living organisms on Mars, but they are looking for previous signs of life on the planet. Before discussing more about missions, let's go back to the beginning.
Mars formed about 4.5 billion years ago with the rest of the solar system and has a solid crust, rocky mantle, and central core like the other inner rocky planets. The Red Planet orbits the Sun at an average distance of 1.5 AU or 142 million miles, compared to Earth's distance of 1 AU or 93 million miles. Mars is about half the size of the Earth. Mars is named after the Roman god of war and gets its red color from iron minerals on its surface that oxidize.
Even though Mars is only half the size of the Earth, it still has some incredible features. Mars has the largest and deepest known canyon in the solar system, called Valles Marineris. This canyon is more than 3000 miles long which would stretch from California to New York. Valles Marineris is over 200 miles at its widest and about 4.5 miles at its deepest point. The Grand Canyon is about the size of one of the fissures of Valles Marineris. Mars is also home to the largest known volcano in the solar system, Olympus Mons. This volcano is over three times taller than Mount Everest and has a base about the size of New Mexico. With a modest-sized telescope, both of these features can be seen from Earth.
Mars has two small moons, which may be captured asteroids. Both moons are shaped like potatoes due to their small size and lack of gravity, which is needed to create spherical objects naturally. Phobos, the largest and closest moon to Mars, is slowly getting closer to the planet's surface. It is estimated that Phobos will crash into the Red Planet in about 50 million years. The smaller and further out moon, Deimos, orbits Mars at about two and half times the distance as Phobos. Deimos and Phobos get their names from the horses that pulled the chariot of the Greek god of war, Ares.
The Red Planet's day is similar in length to a day on Earth. Mars takes 24.6 hours to complete one revolution about its axis, whereas the Earth takes 23.9 hours. A day on Mars is called a "sol" instead of a day. A Martian year is comprised of 669 sols or approximately 687 Earth days. Mars has a tilt similar to that of the Earth. Due to this tilt, Mars experiences seasons like the Earth, but unlike Earth, the seasons vary in length. The longest season on Mars is spring in the northern hemisphere (autumn in the southern hemisphere), while the shortest season is autumn in the northern hemisphere (spring in the southern hemisphere). This inconsistency is due to a more elliptical, or egg-shaped, orbit around the Sun.
As previously mentioned, there have been many missions to Mars; in fact, Mars is the only known planet to be completely inhabited by robots! There are currently two rovers and one helicopter (about the size of a drone) on the surface and eight spacecraft orbiting the Red Planet. Future NASA missions include a sample-return mission, with help from the European Space Agency (ESA). The samples have already been collected by the Perseverance Rover, with the current plan to have the sample returned by the mid-2030s. The next mission by NASA, with help from other commercial and international agencies, will be to get the first humans to Mars. This mission will likely be a one-way ticket for the chosen astronauts. Would you go?
Check back soon for my next Monthly Night Sky Report!
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| Now get outside and look up! |
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