In late March, I traveled to Puerto Rico to conduct observations of Venus using the Arecibo Observatory telescope. It was the second time I traveled to the observatory to make radar measurements of the surface of Venus. Even though it was my second time there, the size and capability of the telescope still impressed me; the telescope is largest single-aperture telescope ever constructed.
Astronomy enthusiasts around the world are gearing up for Tuesday’s celestial show: the transit of Venus across the face of the Sun. The small black dot of Venus, silhouetted against the bright Sun, will be visible with safe solar telescopes and, to those with especially good vision, with the naked eye when protected by eclipse glasses.
If you visit the Public Observatory during its daytime hours in May (1–3pm on Wednesday through Saturday, weather permitting), you can use the 16” telescope to observe an object which looks a lot like the Moon. Hanging in a blue sky, it shines with yellowish reflected sunlight.
We are all familiar with the climate on Earth: the seasons, the range of surface temperatures that are just right for being a water world, the oxygen we breathe, the ozone layer that protects us from UV radiation. In short: habitable. So what other bodies in the Solar System might be (or might have been) habitable, and why aren’t they today? Mars probably comes to mind, and for good reason. Mars has the most similar climate to our own, with water ice caps at the poles, seasonal snow, and dust storms. This is because Mars has a similar axial tilt as the Earth, which creates similar seasonal temperature variations.