earthshine
noun
earth·shine ˈərth-ˌshīn 
: sunlight reflected by the earth that illuminates the dark part of the moon
Because the moon will be near half phase, earthshine will brighten the dark portion of the moon. 
Astronomy
Astronomycalled also earthlight
Example Sentences
Recent Examples on the Web Their results were in line with earthshine fluctuations measured by the CERES satellite, which is part of the NASA's Earth Observing System (EOS). Jamie Carter, Forbes, 6 Dec. 2021 Measured from the Big Bear Solar Observatory in California between 1998 and 2017, the researchers monitored the precise daily, monthly, seasonal, yearly and decadal changes in Earth’s albedo using earthshine. Jamie Carter, Forbes, 6 Dec. 2021 The amount of earthshine will vary from night to night and season to season. Jennifer Gray, CNN, 4 Oct. 2021 In a shocking turn of events, the last three years of their study showed the earthshine had gone down dramatically. Jennifer Gray, CNN, 4 Oct. 2021 The conclusion came from a group of researchers that studied two decades' worth of data on earthshine, or the light reflected off Earth that illuminates the moon. Jordan Mendoza, USA TODAY, 4 Oct. 2021 On the moon, that means from bright sunshine to dim earthshine. Popular Mechanics Editors, Popular Mechanics, 20 July 2019 This effect is caused by earthshine — the light of the sun shines on the Earth and reflects upon the moon. Dean Regas, USA TODAY, 23 Oct. 2017 See More
Jamie Carter, Forbes, 6 Dec. 2021 Measured from the Big Bear Solar Observatory in California between 1998 and 2017, the researchers monitored the precise daily, monthly, seasonal, yearly and decadal changes in Earth’s albedo using earthshine. Jamie Carter, Forbes, 6 Dec. 2021 The amount of earthshine will vary from night to night and season to season. Jennifer Gray, CNN, 4 Oct. 2021 In a shocking turn of events, the last three years of their study showed the earthshine had gone down dramatically. Jennifer Gray, CNN, 4 Oct. 2021 The conclusion came from a group of researchers that studied two decades' worth of data on earthshine, or the light reflected off Earth that illuminates the moon. Jordan Mendoza, USA TODAY, 4 Oct. 2021 On the moon, that means from bright sunshine to dim earthshine. Popular Mechanics Editors, Popular Mechanics, 20 July 2019 This effect is caused by earthshine — the light of the sun shines on the Earth and reflects upon the moon. Dean Regas, USA TODAY, 23 Oct. 2017 See More Word History
First Known Use
1834, in the meaning defined above