Texas (MOL): It is an embarrassing error for a space agency - confusing the sun and moon. Nasa tweeted its 1.2 million followers with this stunning image, claiming to show the sun and Earth. However, it was soon forced to delete the tweet - and experts pointed out the ‘shiny’ area was actually the moon, make bright by the picture’s long exposure. The problem was initially spotted when people realised stars are clearly visible around the ‘sun’. Emily Lakdawalla, planetary scientist and senior editor of The Planetary Society, told Mashable. ‘Well, seeing as how stars and city lights at night are both visible in the field of view with the bright light source, it can’t possibly be the sun.’ Just a few months ago, scientists made the exact same mistake, similarly calling the moon the sun in another tweet. Scott Kelly, who took the image, has been a prolific snapper from space. Earlier this week Scott Kelly got so excited when this everyday view was photobombed by both the moon and Venus. He tweeted two images of the alignment, 12 hours apart, as the station orbited towards the US and journeyed over Texas. Venus was particularly visible overnight because of its ‘high albedo’.

Albedo is the amount of light the planet reflects back into space and comes from the permanent cloud layer that surrounds it. These clouds reflect around 75 per cent of the sunlight they receive back toward Earth, and this reflected light explains why the planet appears so bright in Mr Kelly’s images. The moon looks equally bright because of reflected sunlight, and also looks larger due to its proximity to the station. In reality, the moon has a radius that is three-and-a-half times smaller than Venus.

In fact, the moon is the only object in the night sky brighter than Venus. Mr Kelly, together with cosmonaut Mikhail Kornienko, boarded the ISS in March and are part of a first-of-its-kind experiment to test how the human body copes with prolonged space travel.

In the first, posted at 4.42pm GMT yesterday, the 51-year-old wrote: ‘Day 166. #Venus photobombed the #Moon tonight. Good night from @space_station! #YearInSpace.’ The second was posted this morning and said: ‘Good morning Texas! Great view of you, the moon, and Venus this morning.’