{"id":57756,"date":"2024-04-17T13:29:25","date_gmt":"2024-04-17T13:29:25","guid":{"rendered":"http:\/\/3417413c-9afa-4177-ab9d-b03bc7502893"},"modified":"2024-04-17T14:08:26","modified_gmt":"2024-04-17T14:08:26","slug":"light-from-earth-illuminates-the-unlit-portion-of-the-moon-its-called-earthshine-and-this-is-how-to-see-it","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/light-from-earth-illuminates-the-unlit-portion-of-the-moon-its-called-earthshine-and-this-is-how-to-see-it\/","title":{"rendered":"Light from Earth illuminates the unlit portion of the Moon. It’s called earthshine, and this is how to see it"},"content":{"rendered":"

How to spot earthshine, when light reflected off Earth lights up the Moon\u2019s dark side. <\/p>

By Pete Lawrence\n <\/p>

Published: Wednesday, 17 April 2024 at 13:29 PM<\/p>

\n\n

Earthshine is a phenomenon that allows us to see the dark, night side of the Moon. To understand the effect, it\u2019s important to be able to imagine what Earth looks like from the Moon. <\/p>

Our planet is more reflective than the Moon by quite some margin. Although you might not think it, the Moon\u2019s reflectivity is about the same as an asphalt road.<\/p>

Earthshine by Brian.M.Johnson, Kelling Heath, uk Equipment: Sky 90, Canon 50d, Tripod<\/figcaption><\/figure>
Earth is also approximately four times larger than the Moon. Put together it\u2019s not hard to imagine that Earth would appear big and bright as seen from the lunar surface.<\/p>
What about the phase of Earth? We\u2019re all familiar with the phases of the Moon<\/a> caused by the varying Moon-Earth-Sun angle as our neighbour travels around its orbit, but what would Earth look like from the Moon?<\/p>
It too would go through a complete set of phases but these will be the complementary ones to what we see from Earth.<\/p>
When the Moon is full in our sky, Earth will be new in the Moon\u2019s sky. When the Moon is a thin crescent, Earth would appear with a large gibbous phase.<\/p>
$\"Arrows$
Arrows show the weak earthshine-lit portion of a waxing gibbous Moon. Credit: Pete Lawrence<\/figcaption><\/figure>
The thin crescents we see just before and after new Moon therefore represent times when Earth\u2019s light shining onto the Moon is at its strongest.<\/p>
Earth’s light illuminates the dark, night portion of Moon and reflects back to Earth, allowing us to see the lunar night hemisphere glowing gently. This is earthshine.<\/p>
Another, more poetic term for earthshine is \u2018the old Moon in the young Moon\u2019s arms\u2019, describing the appearance we get with the early evening crescent Moon when it reappears just after the new phase.<\/p>
$\"The$
Earthshine on the Moon by Clive Hollinshead, UK.<\/figcaption><\/figure>
**Observing Earthshine<\/strong><\/h2>**Looking at the earthshine-lit portion of the lunar disc with a scope it is just possible to see certain features. The most obvious is the bright crater Aristarchus<\/a> near to the western limb. <\/p>
Photography is another excellent way to reveal features within the lunar night.<\/p>
Deliberately over-exposing a bright lunar crescent will reveal many details from the \u2018dark side\u2019, rendering the night portion as detailed as it appears when properly lit.<\/p>
It\u2019s pretty easy to see and photograph the earthshine-lit portion of the Moon when the Moon is showing as a thin crescent, but how close to full Moon can you get and still record the effect.<\/p>
**Pictures of Earthshine<\/strong><\/h2>**Below is a selection of photos of Earthshine captured by *BBC Sky at Night Magazine<\/em> readers and astrophotographers. For advice on lunar imaging, read our guide on* *how to photograph the Moon<\/a> or our beginner’s guide to astrophotography<\/a>.<\/p>*
*And don’t forget to send us your images or share them with us via Facebook<\/a>, Twitter<\/a> and Instagram<\/a>.<\/p>*
$\"Earthshine$
Earthshine during the April 8 total solar eclipse, captured with several long and short exposures by Harley Grady, Hillsboro, Texas, USA. Equipment: TS Optics CF APO 90mm refractor, Fuji XH2 mirroless camera.<\/figcaption><\/figure><\/div><\/div>
$\"A$
A thin crescent Moon exhibiting Earthshine setting over ESO\u2019s Paranal Observatory in Chile, 27 October 2011. Credit: ESO\/B. Tafreshi (twanight.org)<\/figcaption><\/figure><\/div><\/div>
$\"Also$
Also known as the Da Vinci Glow, earthshine allows us to see features on the Moon\u2019s dark side. Credit: Pete Lawrence<\/figcaption><\/figure><\/div><\/div>
$\"The$
The High Dynamic Moon by Luke Oliver, Grays, Essex, UK. Equipment: Skywatcher 200P, Canon 1000D.<\/figcaption><\/figure><\/div><\/div>
$\"The$
The Solar corona during the 21 August 2017 total solar eclipse by Alex Conu, Castle Garden, WY, USA. Equipment: Canon EOS 5D Mark III, Pentax 75 SDHF refractor<\/figcaption><\/figure><\/div><\/div>
$\"St.$
St. Raphael and the Moon by Paco Bellido, Cordoba, Spain. Equipment: Canon EOS 550D, Sky Watcher ED80 refractor.<\/figcaption><\/figure><\/div><\/div>
$\"Waning$
Waning Crescent Moon 11% lighting, with focus on area not lit by Fernando Oliveira De Menezes, Sao Paulo, Brazil. Equipment: Esprit 150 ED, ASI 1600mm cooled<\/figcaption><\/figure><\/div><\/div>
$\"Earthshine$
Earthshine Moon with Skywatcher 150\/750 by Houssem Ksontini, Tunis, Tunisia. Equipment: Skywatcher 150\/750, Nikon D5300<\/figcaption><\/figure><\/div><\/div>
$\"Lunar$
Lunar Earthshine by Honor Wheeler, Wilmington, Kent, UK. Equipment: Canon EOS 1100D, Canon EF-S 55-250mm lens.<\/figcaption><\/figure><\/div><\/div>
$\"Earthshine$ <\/figure><\/div><\/div>
$\"The$
The Moon by Clive Hollinshead, UK. Equipment: Canon eos 1200D, 70-300mm lens, tripod.<\/figcaption><\/figure><\/div><\/div>
$\"Crescent$
Crescent Moon and Earthshine by Ron G, Stafford, UK. Equipment: Canon 1200D, tripod, Tamron 70-300mm lens <\/figcaption><\/figure><\/div><\/div>
$\"Purple$
Purple Haze by Kirk Macey, Cranleigh, Surrey, UK. Equipment: 120mm Skywatcher refracter, Canon 450D, Fringe Killer Filter.<\/figcaption><\/figure><\/div><\/div>
$\"Earthlight$
Earthlight by Martin Rogers, Edgcott, Buckinghamshire, UK. Equipment: Celestron C8N, Pentax K5 at prime focus, motorised CG5 mount<\/figcaption><\/figure><\/div><\/div>
$\"Setting$
Setting Moon with Earthshine by Steve Brown, Stokesley, N. Yorkshire, UK. Equipment: Canon 600D, 250mm lens, tripod. <\/figcaption><\/figure><\/div><\/div>
$\"Earthshine$
Earthshine by Tom Howard, Crawley, Sussex, UK. Equipment: Nikon D7000, Meade 5000 127mm refractor, EQ6.<\/figcaption><\/figure><\/div><\/div>
$\"Earthshine$
Earthshine 3rd September 2013 by Aprill Harper, Blunham, Bedfordshire, UK. Equipment: Samsung NX1000, SkyWatcher 8″ Dobsonian<\/figcaption><\/figure><\/div><\/div>
$\"Starry$
Starry Earthshine by Brendan Alexander, Donegal, Ireland. Equipment: Canon 1000D, Omni XLT 150, CG5<\/figcaption><\/figure><\/div><\/div><\/div>