Derived from the Latin oppositio (“to oppose”), the term “opposition” is primarily used in a political context. The parties involved in a government face the so-called opposition parties. Astronomers also use the word opposition. They describe a certain constellation of celestial bodies. If a planet is located exactly on the line formed by the sun and the earth, the researchers speak of an opposition position or simply of an opposition of this planet.
On the night of December 8th, the red planet Mars will reach its opposition and will then be particularly easy to observe. It is directly opposite the sun and will shine all night as the brightest “star” in the sky.
The reason for this is the particularly small distance between Mars and Earth during an opposition, which occurs every 26 months due to the orbital speeds of the two planets. However, Mars does not have the same brightness at every opposition, because the distance between Earth and Mars varies from time to time, since the orbits of the two planets are elliptical.
On December 8, the distance between Earth and Mars is particularly small at 81.5 million kilometers. In this decade there will be no better way for amateur astronomers to observe the planet Mars. It will shine near the star Aldebaran in the constellation Taurus with a magnitude of 1.8 – brighter than Sirius, the brightest star in the night sky. Aldebaran and Mars appear reddish in the telescope or binoculars.
The next Mars opposition will already occur in January 2025, but it will not be until 2033 that Mars will shine again as brightly as this year. In the case of oppositions, the distance between Earth and Mars is generally particularly small, but the point in time of the smallest distance does not exactly coincide with the opposition. In fact, the shortest distance between Earth and Mars at the current opposition was already reached on December 1st.
The Mars opposition of December 8 is a special event for another reason. Not only Mars, but also the Moon is in opposition tonight. In the case of the moon, however, there is a more common term for this: a lunar opposition is nothing more than a full moon.
There will be a rare opportunity to see a brightly lit Mars next to the Full Moon on Thursday night. But that’s not all. The culmination of the night of double opposition is what is known in English as occultation: the full moon moving across the sky will slide over Mars and then eclipse it for a time before the red planet on the other side of the moon returns to earthly ones observer becomes visible.
The exact time of this occultation and its duration depends a little on the location – but in principle this cosmic spectacle can be observed everywhere in Germany and almost all of Europe. For example, as seen from Berlin, Mars will disappear behind the moon at 6:01 a.m. and will not reappear until 6:55 a.m. So it is important to set the alarm early. But even if you miss the start of the occultation, it’s still worth watching the red planet’s return.
Of course, all of this depends on whether the weather cooperates. Unfortunately, if the sky is overcast, you won’t notice anything of the cosmic spectacle. In this case, there is at least the possibility of marveling at the duet of Mars and Moon on the Internet at “The Virtual Telescope Project”.
And if you happened to be traveling this week, you could be in a place with better weather than in Germany. Mars occultation will be seen across most of North America, the North Atlantic and Europe, as well as northern Mexico and North Africa. On the American continent, the spectacle will already take place on the evening of December 7th.
“Aha! Ten minutes of everyday knowledge” is WELT’s knowledge podcast. Every Tuesday and Thursday we answer everyday questions from the field of science. Subscribe to the podcast on Spotify, Apple Podcasts, Deezer, Amazon Music, among others, or directly via RSS feed.
