MANITOBA SKIES – FEBRUARY 2020
Contributed by Ray Saltel, Science Communicator
February skies bring a chance to see the innermost planet, which means that all five of the major naked-eye planets can be seen in a single dusk-to-dawn night. There’s also a rare eclipse of the planet Mars by our Moon, and an extra day in February. Read on to learn more!
This February will offer one of the best chances of the year to view Mercury, a planet usually hidden in the twilight glow because it always appears close to the Sun in our sky. However, there are a number of factors, when working together, that can make the elusive planet visible. Here’s how you can track down the closest planet to the Sun yourself, without any special equipment.
One factor is how far Mercury appears to be away from the Sun as viewed from the Earth. As Mercury orbits the sun, there are two points in Mercury’s orbit where the planet will appear as far away from the sun as possible. These points are called “Greatest Eastern Elongation” and “Greatest Western Elongation”, depending on whether it appears east or west of the sun from our viewpoint on Earth. In general, Mercury will only be visible for a week or two around the times of greatest elongation. Eastern elongations will be seen in our evening sky after sunset, and western elongations will be seen in our morning sky before sunrise. (By the way, this applies to the other inner planet, Venus, too!)
Another factor is the position of the ecliptic which changes with time. The ecliptic is the apparent path the Sun follows through the constellations from the perspective of the Earth. One can imagine the ecliptic as a great circle projected onto the sky. The Sun, Moon and visible planets will always be found on or very close to the ecliptic. If the angle between the ecliptic and horizon is shallow, any planet near the Sun will be located at a low altitude above the horizon, and will be difficult to see. If the angle between the ecliptic and horizon is steep, any planet near the Sun will be located at a higher altitude above the horizon, and is more likely able to be observed. See the image below for a comparison.
Conditions to view Mercury are favorable in the early part of the month because the planet will be at “Greatest Eastern Elongation” on February 10th at the same time that the ecliptic is inclined at a high angle with the horizon. It should be visible for a week or so on either side of this date, as it first rises up out of the sunset colors, and then sinks back down. Venus provides a handy reference point so you know where to look.
Venus will appear in the southwest shortly after sunset and will dominate the evening skies of February. With the exception of the Moon, Venus will be the brightest object visible in the night sky. At the beginning of the month Venus will set 4 hours after the Sun does and by the end of the month it will set just under 5 hours later.
Saturn, Jupiter and Mars will be close enough to each other in the sky to form a small line of planets which will be visible in the southeast a little before sunrise. Saturn will be the lowest of the three planets, on the left, with Jupiter in the middle and Mars on the right and slightly higher. Saturn, Jupiter and Mars will be seen for an increasingly longer period of time as the month progresses.
On the morning of February 18th, the thin crescent moon will pass in front of the planet Mars for observers in North America. When the Moon passes in front of the Sun, we call it an eclipse; the general term for the Moon covering any other celestial object is an occultation. The event is visible across most of North America, but conditions in Manitoba are not great: the event occurs just 40 minutes before sunrise in a bright sky. You’ll probably need binoculars or a telescope to see the event. Folks farther west will have the event occur in a darker sky. Visit the International Occultation Timing Association (IOTA) page on this event to see circumstances for other locations across the country.
The Moon will also be close to Jupiter on the morning of February 19th, and close to Saturn on the morning of February 20th.
FEBRUARY 2020 SKY EVENTS
Sat Feb 1: The month begins with the Moon at First Quarter phase.
Sat Feb 8 (evening sky): The Moon will be near the Beehive cluster, an area of the sky containing about a thousand stars located within the constellation of Cancer the Crab. Check it out in binoculars and you’ll see it as a fuzzy patch sprinkled with stars; a telescope will show more than a hundred stars in a beautiful cluster.
Sun Feb 9: The Full Moon phase occurs on this day.
Mon Feb 10 (evening sky):
Mercury will be at “Greatest Eastern Elongation” (see the Solar System section above). While this will be the best time to look for Mercury, one can attempt to look for the planet on the days leading up to and after the 10th. Because Venus is very bright, it can be used as a guide to help find Mercury since both planets will be in the same general direction of the sky after sunset. Venus will be high up in the southwest while Mercury will be much lower and to the west of Venus.
Sat Feb 15: The Moon is at Third Quarter phase.
Night of Mon Feb 17/Tue Feb 18 (morning sky): The Moon will occult the planet Mars (see Solar System section above). Observers in favorable parts of North America will have the opportunity to witness the Moon passing over Mars.
Night of Tue Feb 18/Wed Feb 19 (morning sky):The Moon will be close to the planet Jupiter.
Night of Wed Feb 19/Thu Feb 20 (morning sky): The Moon will be close to the planet Saturn.
Sun Feb 23: The New Moon phase occurs on this day. The week around new moon is is a good time to observe deep sky objects like nebula, galaxies, and star clusters because the Moon is out of the sky for most of the night.
Thu Feb 27 (evening sky): On the evening of February 27th the Moon will be close to the planet Venus.
Sat Feb 29: This February is 29 days long because 2020 is a leap year. This means that 2020 is 366 days long instead of 365. February 29th is the extra day added to the year and is called a leap day. We add leap days because the earth’s orbit around the sun, which is tied to the seasons, isn’t an even number of days. It actually takes 365 and a quarter days to go around the sun, and that quarter day would build up each year, and eventually we would have winter in June. For more on how we keep our calendar in sync with reality, visit this page.
To see when the International Space Station passes over southern Manitoba, click here.
You can find times for other locations across Manitoba and throughout the world, as well as times for other orbiting objects, by visiting Heavens-above.com and entering your location here.