Astronomy Picture Of the Day (APOD)APOD: 2023 May 29 Б Milky Way over a Turquoise Wonderland
What glows there? The answer depends: sea or sky? In the sea, the unusual blue glow is bioluminescence. Specifically, the glimmer arises from Noctiluca scintillans, single-celled plankton stimulated by the lapping waves. The plankton use their glow to startle and illuminate predators.
APOD: 2023 May 28 Б Ida and Dactyl: Asteroid and Moon
This asteroid has a moon. The robot spacecraft Galileo on route to Jupiter in 1993 encountered and photographed two asteroids during its long interplanetary voyage. The second minor planet it photographed, 243 Ida, was unexpectedly discovered to have a moon.
Crescent Neptune and Triton
Gliding through the outer Solar System, in 1989 the Voyager 2 spacecraft looked toward the Sun to find this view of most distant planet Neptune and its moon Triton together in a crescent phase. The elegant image of ice-giant planet and largest moon was taken from behind just after Voyager's closest approach.
Virgo Cluster Galaxies
Galaxies of the Virgo Cluster are scattered across this nearly 4 degree wide telescopic field of view. About 50 million light-years distant, the Virgo Cluster is the closest large galaxy cluster to our own local galaxy group.
Cat s Eye Wide and Deep
The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its more familiar outlines are seen in the brighter central region of the nebula in this impressive wide-angle view. But this wide and deep image combining data from two telescopes also reveals its extremely faint outer halo.
APOD: 2023 May 24 Б Observatory Aligned with Moon Occulting Jupiter
Sometimes we witness the Moon moving directly in front of -- called occulting -- one of the planets in our Solar System. Earlier this month that planet was Jupiter. Captured here was the moment when Jupiter re-appeared from behind the surface of our Moon.
APOD: 2023 May 23 Б Jupiters Swirls from Juno
Big storms are different on Jupiter. On Earth, huge hurricanes and colossal cyclones are centered on regions of low pressure, but on Jupiter, it is the high-pressure, anti-cyclone storms that are the largest. On Earth, large storms can last weeks, but on Jupiter they can last years.
APOD: 2023 May 22 Б Supernova Discovered in Nearby Spiral Galaxy M101
A nearby star has exploded and humanity's telescopes are turning to monitor it. The supernova, dubbed SN 2023ifx, was discovered by Japanese astronomer Koichi Itagaki three days ago and subsequently located on automated images from the Zwicky Transient Facility two days earlier.
APOD: 2023 May 21 Б Tardigrade in Moss
Is this an alien? Probably not, but of all the animals on Earth, the tardigrade might be the best candidate. That's because tardigrades are known to be able to go for decades without...
Galileo s Europa
Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo...