The best of astronomy this month: watch the Moon pass by Jupiter, Mars, Antares and Saturn.
By Dhara Patel, Astronomy Education Officer
(Details given are for London and may vary for other parts of the UK).
Top three things to see this month
1st Feb - Catch the waning gibbous moon beside the bright star Regulus.
7th - 11th Feb - Watch the Moon pass by Jupiter, Mars, Antares and Saturn.
23rd Feb - Look for the Moon close beside Aldebaran just after the occultation.
Look Up! Podcast
As well as taking you through what to see in the night sky each month, Royal Observatory Greenwich astronomers pick their favourite astro news story. For February, they're chatting about the first observations of stellar details on a star other than our Sun and a potential new definition for a planet which takes into account the upper mass limit of these objects.
To begin the month catch the large waning gibbous moon passing close to the bright star Regulus in the constellation of Leo. Look to the east in the early evening. You'll see a group of stars in this constellation that make up a 'mirrored question mark' looking pattern – an asterism called ‘the sickle’ and Regulus lies at the bottom point of this. Regulus is actually a multiple star system – 4 stars split into two pairs of stars. The main star is blue-white in colour and thought to be a white dwarf star (a small, dense star – one which our Sun will turn into at the end of its life).
Due to the full moon falling on the 31st January and with February only having 28 days we won’t see a full moon this month – the lunar cycle takes 29.5 days. Although a full moon can be a delightful sight astronomers often prefer the last quarter or first quarter moon to look at craters on its surface or a new moon to view deep sky objects because there is little moonlight to interfere. On the afternoon of the 7th, the Moon reaches last quarter. It won’t be visible in the evening – so catch it in the pre-dawn hours of that morning or wait until a few hours before the Sun rises on the 8th to see it in the south-eastern sky. The boundary between the light and dark sides of the Moon, called the terminator, should be clearly visible and this is the best place to look for craters on the Moon as the shadows cast from the crater walls make them easier to spot. Crack out your binoculars or a telescope if you have one to see the details on its surface.
7 - 11 February
Follow the Moon in the early hours before sunrise from the 7th to the 11th of February when it will be in its waning crescent phase. You could watch it glide past Jupiter, then Mars and the red star Antares in the constellation of Scorpius and finally Saturn over the course of these few mornings. Look to the south-east and try and get to an open area with no trees or buildings to obscure your view of this part of the sky as these objects will be close to the horizon, especially Saturn. The planets look like bright stars to the naked eye and if you watch them over a few weeks (particularly Mars – as it moves quicker than the other two), you’ll see that the planets wander the sky. It’s easy to see why the planets were called ‘wandering stars’ in the past.
In the evening, the waxing crescent moon will be in the constellation of Taurus the bull in the south-west and close-by will be the red giant star Aldebaran. This star is no longer fusing hydrogen gas in its core like our Sun; it’s a more evolved star and has expanded to 44 times the diameter of our Sun. The Pleiades will also appear nearby. This is a young open cluster of stars and are often known as the seven sisters (as with just your eyes and a clear sky, you should be able to spot seven individual points of light in this cluster). However the Pleiades is home to hundreds of young, very hot, blue stars which you can start to see with the aid of binoculars or a telescope.
By the afternoon of the 23rd, the Moon will have moved to occult Aldebaran. An occultation happens when one object appears to be hidden by another. In this case the Moon is much closer to us than Aldebaran, so when both appear in the same part of the sky, the Moon hides Aldebaran from our view. The occultation peaks in daylight hours but you may be able to see Aldebaran coming back into sight as the Sun sets and the skies gets darker. Aldebaran will be occulated nine times in 2018 because, it (like a few other stars including Regulus), lie close to the ecliptic. This circle in the sky represents the Sun’s apparent path during the year which is also similar to the apparent paths of the planets and the Moon.
The Moon's phases this month
- 7 Feb - last quarter moon (3:54pm)
- 15 Feb - new moon (9:05pm)
- 23 Feb - first quarter moon (8:09am)
See the other amazing photographs from the 2017 Insight Astronomy Photographer of the Year competition in our free exhibition like Moonrise at the Pier by Sergio Garcia which was highly commeneded for our Moon category in 2016
- When looking at faint objects such as stars, nebulae, the Milky Way and other galaxies it is important to allow your eyes to adapt to the dark – so that you achieve night vision.
- Allow 15 minutes for your eyes to become sensitive in the dark and remember not to look at your mobile phone or any other bright device when stargazing.
- If you are using a star app on your phone switch on the red night vision mode.
- Need a stargazing telescope or decent binoculars? Check out our range of high-quality observing equipment recommended by Royal Observatory astronomers:
Share your astronomy pictures
Congratulations to Phil Salisbury for his beautiful image of the night sky. He shared this image on our astrophotography Facebook page and we chose it for February's banner image.
If you want to be in with a chance to showcase your astrophotography skills on the banner of next month's night sky blog, share your photos via our Royal Observatory Astrophotography Facebook group
You can also connect with us on Twitter @ROGAstronomers
Insight Astronomy Photographer of the Year
Come and see the amazing entries and winner to the world’s biggest astrophotography competition in our free exhibition at the Royal Observatory.
If you've been inspired by the images from last year's competition then get involved this year. Enter your astronomy images for the chance to win cash prizes and have your worked featured in our 2018 exhibition. This year's competition closes midday 9 March 2018.
See more of the night sky
Come on an amazing tour of this month's night sky in our Sky Tonight live planetarium show.
Central image: © Phil Salisbury
Resources for teachers and students
The Royal Observatory learning team have also created:
- Free animated videos that answer the biggest questions in astronomy and resources to go alongside them.
- A whole host of podcasts featuring interviews with real space scientists, astronauts, and active researchers working in UK Universities.
- During the winter months we hold Think Space Lectures - we invite active researchers in the field of physics and astronomy to come and talk about the new research they are doing. School tickets are free.