What looked like a tiny black ball skimmed past the vast, burning surface of the Sun in incredible NASA pictures captured this week.
Mercury was spotted making a rare ‘transit’ past the sun - the last until 2032.
The images were captured by NASA’s Sun-watching satellite the Solar Dynamics Observatory (SDO).
The smallest planet in the solar system could be seen as a tiny black disc moving across the glowing orb, starting in the UK at just after 12.35pm on Monday.
The last time Mercury passed the Sun this way was in 2016, but the next is not due until 2032.
Stargazers used solar-filtered binoculars and telescopes to spot Mercury - a tiny black dot - as it passed directly between Earth and the Sun on Monday.
At Cape Canaveral, space buffs got a two-for-one.
As Mercury's silhouette graced the morning Sun, SpaceX launched 60 small satellites for global internet service, part of the company's growing Starlink constellation in orbit.
NASA revealed some of the first images of the transit, taken from its satellite monitoring the Sun.
Every 88 days Mercury completes each orbit around the Sun, and it passes between the Earth and the Sun every 116 days.
Because the planet's orbit around the Sun is tilted, it normally appears to pass above or below our nearest star.
Q: What did Mercury say when it was asked to line up between Earth & the Sun?— NASA (@NASA) November 12, 2019
A: I'll pass! 😎
We witnessed a rare treat during today's #MercuryTransit, which only happens ~13 times a century! Revel in the views captured our @NASASun-observing satellite: https://t.co/Wm7TYlNSeX pic.twitter.com/UqhYHTpAQm
A transit can only take place when the Earth, Mercury and the Sun are exactly in line in three dimensions.
Looking at the Sun without appropriate protection, either during the transit or at any other time, can cause serious and permanent damage to the eyes.