No talk of ‘supermoons’ this month! February’s 28 days are shorter than the lunar ‘month’. With the lack of a full moon in February, there may be little note of lunar perigee occurring just two days and ten hours before the next full moon on March 1st.
The bright planet trifecta in our southern skies gets going in February, with Jupiter, Mars and Saturn as the (non-stellar) stars of our show.
Jupiter reaches its highest altitude at the break of dawn, only 30 degrees above our southern horizon. With Jupiter at quadrature, 90 degrees from the sun, it rises in the middle of the night and its moons do marvelous disappearing and reappearing acts in Jupiter’s shadow and behind the planet. Some of the best mornings are on the 4th, 6th, 13th, 24th and 17th, for Western Hemisphere locations. See http://wwwcdn.skyandtelescope.com/wp-content/uploads/WebJphenTab2018.pdf for a full set of times. Any telescope will show most of these events. Just for fun, on one of those mornings, follow Jupiter in the daytime sky and see how long you can spot it.
Mars seems lost. At magnitude plus 1, it doesn’t stand out much in the dawn sky. While its tiny size (6 arc seconds) makes it a featureless orb in all but the largest telescopes in the steadiest skies, it looks noticeable lopsided in any telescope. It stays lopsided, around 90 percent sunlit, through April. By then, Mars will appear almost twice as large as it is now, on its way to 24 arc seconds wide, during what will become known as the summer of the giant planets!
February is a good month to compare Ares (Mars) nearby its rival anti-Ares (Antares). They are both about magnitude plus 1.0. How are they different? Antares shimmers as a point source of light and Mars’ light is steadier, averaged out as it is spread across tiny variations in our atmosphere.
Saturn completes the trifecta, low in the southeast, but worth a glance if you are already out to see Jupiter. On the morning of the 11th Saturn floats under the thin moon.
Mercury and Venus are deep in the sun’s glare. Watch early in March as these two pop up together into bright evening twilight.
The two brightest of the are-they-or-are-they-not-really-members of the planet club are Minor Planet Ceres, near Mars in our skies, and asteroid Vesta, in the evening skies in Cancer. The Dawn spacecraft visited both of these tiny worlds. Ceres and Mars are almost the same distance from Earth this month, but Mars is seven times larger in diameter and Ceres and Vesta are a dim, but findable in binoculars, magnitude plus 7.
The Milky Way still arches high across our evening skies. We are looking out the backdoor of our galaxy, so the pale stream of stars is fainter than the summerside view. We are lucky to have the Orion arm of the galaxy draped across our sky. This relatively nearby swath of stars and gas and dust in the extended darkness of winter nights makes this season highly anticipated by stargazers.
Eclipse fans only get a partial solar eclipse on the 15th, visible from Antarctica and southern South America. The next chance for us is a middle of the night total lunar eclipse in January 2019. This month, the last quarter Moon sits between Jupiter and Mars in our morning skies on the 8th. A tiny crescent Moon, at lunar apogee, points to Saturn on the 11th.
The International Space Station has a series of evening performances through the 14th. Morning viewings start around the 25th.