Dear Urban Astronomer So, my good friend and I were talking about the temperature in space. He thinks it must be hot in space, since there is no atmosphere to absorb sunlight. I disagreed. I think that the fact that there is no air in space, means there is nothing to heat up. That’s how temperature on earth works. So, surely it must be cold in space. Can you shed light (excuse the pun) on this debate? Can you answer … Continue reading →
The planet Jupiter takes 4331.6 earth days to orbit around the Sun. This means than one Jupiter year equals almost 11.9 Earth years. Because Jupiter rotates so rapidly around its axis, its year lasts 10,501 of its own days. Jupiter has such a long year because it is quite far from the Sun. Not only does this mean it has a longer path to travel on its orbit, but the Sun’s gravity is much weaker at that distance, requiring it … Continue reading →
The planet Mars takes 687 Earth days to orbit the Sun. This means that a martian year lasts 22.9 months, or almost two full Earth years. A martian day is only very slightly longer than an Earth day, so that Mars’ year is 670 martian days long. Mars’s year is longer than Earth’s because it is further from the Sun than Earth is, so that it feels the Sun’s gravity more weakly than the Earth does. This means that it … Continue reading →
The planet Venus takes 224.7 Earth days to orbit the Sun. This means than a Venus year is a little more than seven months long. Interestingly, Venus’ day is slightly longer than its year, and the planet revolves around its axis backwards compared to all the other planets in the Solar System, so that Venus is very close to being tidally locked. In a few hundred million years, that process will complete as tidal forces gradually slow Venus’s rotation enough … Continue reading →
Mercury takes 88 days to orbit around the Sun, which means that one Mercury year lasts less than three Earth months. Mercury has such a short year because it is very close to the Sun. According to Newton’s Law of gravity, this means that the Sun’s gravity is much stronger at Mercury than it is for Earth, and this requires it to move a great deal faster if it is to stay in its orbit, which is why it has … Continue reading →
