At 8:00 AM today, the distance from the center of the Earth to the center of the Moon was 356,592.862 kilometers, marking the closest moment of this year.
Similarly, on the day of the Lunar New Year’s Eve, which is February 13 at 10:00 AM, the Moon will pass its apogee, with a geocentric distance of 406,540.457 kilometers, the farthest moment of this year.
The Moon reaches its full phase (syzygy) at 14:18 on January 30. Globally, because this full moon happens to occur near the closest perigee of the year, from a geocentric perspective, this is the largest full moon of the year.
However, although this full moon occurs near the closest perigee of the year, it is daytime in China at this time, so the Moon cannot be seen; furthermore, (1) the Earth has volume; if the moment of the full moon does not occur during the night in a specific region, the distance from that region on the Earth’s surface to the center of the Moon will be further than the geocentric distance. And (2) by the time the region rotates to the night side and the Moon becomes visible, the Moon will have already moved slightly away from the perigee. Therefore, combining these two factors, for China, the apparent diameter of the full moon seen will not be that large.
Thus, while the full moon on January 30 will look large, for China, it is not the largest visible full moon of the year; in 2010, the largest full moon visible to us (where the full moon occurs during the night in Guangdong and near the lunar perigee) is the full moon at 00:38 on March 1 (12:38 midnight on February 28).
At the same time, today is also the day of Mars opposition. After more than two years of long waiting, we have once again welcomed a busy 4–6 week period for Mars observation. Mars will reach its minimum distance from Earth in nearly two years today.
During this Mars opposition, because Mars is located in Cancer, one of the twelve zodiac signs, it will be nearly at the zenith around midnight. It is less affected by atmospheric turbulence, making the image of Mars more stable, which is a favorable condition for observation.
Please include the original address when reposting: https://kexue.fm/archives/380
For more detailed reposting matters, please refer to: Scientific Space FAQ