Mars' Autumn Approach: Catch a Glance at Opposition this Season
Get ready, stargazers! The planet Mars will reach opposition on January 16, 2025, making it an excellent target for telescopes of all sizes. This celestial event promises a spectacular view, especially for those in Germany, with observations recorded in Neumünster and other parts of northern Germany.
Observing Mars
Mars' opposition occurs when it is directly opposite the Sun in the sky. Its position in its orbit determines its altitude and visibility, making it a viable target for medium and large telescopes when it has an apparent diameter of 6 arcseconds or more. During opposition, Mars will be bright and easy to spot in the night sky.
Mars' Seasons
Astronomers use a quantity called 'areocentric longitude' or 'Ls' to define seasons on Mars. Each of the 12 Martian months is 30 degrees in Ls. The Mars opposition in January 2025 occurs when Ls is approximately 200 degrees, marking the end of the Martian summer in the southern hemisphere. In contrast, the southern polar cap will be very small, having melted over the summer.
The North Polar Cap
When Mars has more of its northern hemisphere tilted towards us, the north polar cap can be observed with medium-sized telescopes. If using optical filters, a blue or violet filter can make the polar ice caps and the clouds stand out. The large volcanoes in the Tharsis plateau also attract white clouds, forming distinctive 'W'-shaped cloud patterns.
Dust Storms on Mars
Mars is known for its dust storms, which can start anywhere but tend to originate in the south. During the Martian dust storm season, which starts at about Ls = 240° and continues to Ls=0°, there are three types of dust storm: local, regional, and global. If a large dust storm does erupt, it is a good idea to record its progress by sketching the region and plotting the size and location of the dust storm as it changes over time.
Phenomena on Mars: Mars Flashes
A fascinating phenomenon on Mars is the 'Mars flashes', brilliant 'starlike' flashes that can last for a number of seconds. These occur in two regions: Edom and Tithonius Lacus. The geometry for Mars flashes to occur is rare and requires Earth and the Sun to be overhead near the zenith over these regions.
When to Look for White Clouds
White clouds on Mars can become quite brilliant and are fascinating to watch, particularly if they are close to the morning limb. September is the time to start looking for white clouds on Mars, particularly in basins like Hellas, Argyre, and Eridania.
Tools for Observing Mars
You can check the Ls of Mars with free software like WinJupos and planetarium software like SkySafari. These tools will help you plan your stargazing sessions and make the most of the Mars opposition in 2025.
During Mars opposition, the planet will be due south at midnight and visible all night. So, mark your calendars, gather your telescopes, and get ready for an unforgettable stargazing experience!