People talk of planets frequently, but sometimes we forget our smaller brothers and sisters in the solar system. There are five main dwarf planets in our solar system. These are (in decreasing size): Pluto, Eris, Makemake, Haumea, and Ceres. All five celestial bodies have been put in their own category other than planets or asteroids. To be a dwarf planet, it must orbit the sun, have enough mass that it forms a spherical shape, not be a moon to a larger body, and cannot be large enough to have cleared all the debris from its path around the sun. For example, Ceres is its own spherical body traveling around the sun. Unfortunately, it also travels with asteroids and meteoroids right beside it, so it has not cleared enough space to become a planet. This doesn’t mean it is not large, though. It has enough mass that it holds as much as a third of all the mass in the asteroid belt.
As we have transitioned into the holiday season, we have been blessed with the beautiful sight of seeing the snow and ice that makes the mountains around us look so sharp. Meanwhile, across our solar system, we have found that another object has been holding ice as well; this is the case on Ceres. We have seen images from the Dawn spacecraft, that has been orbiting Ceres, of places inside some of the craters that house ice. It seems that as the dwarf planet rotates and revolves around the sun, some areas of its craters don’t receive any sunlight at all. With no direct heat source, these dark places can hold deposits of ice. Thomas Prettyman of the Planetary Science Institute in Tucson, Arizona obtains the readings sent from the neutron detector (GRAND) onboard the satellite. With this, he can tell the amount of Hydrogen in the dwarf planet by measuring the number of neutrons leaving the planet. Since Hydrogen slows these neutrons from bouncing away after coming in with sunlight, the relatively small amount leaving, tells us that it has a lot of hydrogen. Such large amounts of hydrogen in ice can lead us to believe that Ceres has water-ice, unlike some ice on Mars that consists of frozen carbon dioxide.
This water was most likely formed on the dwarf planet early in the formation of the solar system. As the surface was bombarded by meteoroids and asteroids, the denser rock migrated to the core which left a large amount of ice to fill the upper region of the dwarf planet. It is estimated that beneath the surface, there’s probably a large deposit of ice. With more bodies being found that have ice, or possible liquid oceans such as Jupiter’s moon Europa, the possibility that we encounter new life also increases.
Heavenly Outlook
For any interested stargazer, there are many constellations that should sound familiar; many of which should be able to be pointed out in the night sky. For example, Ursa Major, or the Big Dipper, is the most common and it is rising out of the north as if it just scooped up water from the horizon. There are others that people should be able to point out, such as Orion, but the main 12 signs of the zodiac are also important. Many people read about them to match themselves with personality charts, but how many people can point them out in the sky?
Beginning right after dawn, seven of the twelve signs can be visible spanning from the northeastern to southwestern horizons. Starting in the east, you should be able to find Orion by his belt (although he is not one of the twelve zodiac symbols). Look to the north, and you might trace two faint lines running parallel to one another. These are the twins, or Gemini. Then if you follow Orion’s belt in a line, you should run into the bright star Aldebaran sitting at the center of Taurus, the bull. Aries the ram comes next but is very faint to see. Still following in line with the others comes Pisces, the fish, skirting around the great square. Aquarius, the water bearer, is next with Mars sitting in the middle of it. Then right on the other side of Venus is Capricorn, the goat. Lastly, Sagittarius, the archer, might barely be breaking the horizon. Many of these constellations may be hard to spot since any are dim, but go out on a clear night and accept the challenge that the stars provide: see how many you can find!