Browse NASA Astronomy Picture of the Day archive by date and media: Archive Discoveries
Browse the NASA APOD archive without needing the exact date first. Filter by media type and keep moving deeper into older images and videos.
A GRB 000301C Symphony
Last March, telescopic instruments in Earth and space tracked a tremendous explosion that occurred across the universe. A nearly unprecedented symphony of international…
The Pulsar Powered Crab
In the Summer of 1054 A.D. Chinese astronomers reported that a star in the constellation of Taurus suddenly became as bright as the full Moon. Fading slowly, it remained visible…
Venus' Evening Loop
From September 2000 through March 2001, astronomer Tunc Tezel patiently photographed the planet Venus on 25 different dates as it wandered through the evening twilight. The…
LINEAR's Tail and Two Nuclei
Arcing toward southern skies in late March, this faint comet LINEAR - the one officially designated C/2001 A2 (LINEAR) - brightened unexpectedly. The outburst, apparently due to…
Stellar Spectral Types: OBAFGKM
Astronomers divide stars into different spectral types . First started in the 1800s, the spectral type was originally meant to classify the strength of hydrogen absorption lines .…
Working in Space
High above planet Earth, a human helps an ailing machine. The machine, in this potentially touching story, is the Hubble Space Telescope , which is not in the picture. The human…
Close-up of the Face on Mars
Wouldn't it be fun if clouds were turtles ? Wouldn't it be fun if the laundry on the bedroom chair was a friendly monster ? Wouldn't it be fun if rock mesas on Mars were faces or…
Comet Hale-Bopp Over Val Parola Pass
Comet Hale-Bopp became much brighter than any surrounding stars. It was seen even over bright city lights . Out away from city lights, however, it put on quite a spectacular show…
NGC 6826: The Blinking Eye
The colorful planetary nebula phase of a sun-like star's life is brief . Almost in the “blink of an eye” - cosmically speaking - the star's outer layers are cast off, forming an…
Saturn The Giant
Forty years ago today (May 25, 1961) U.S. president John Kennedy announced the goal of landing Americans on the Moon by the end of the decade. Kennedy's ambitious speech triggered…
X-Ray Stars of 47 Tucanae
A deep optical image (left) of 47 Tucanae shows an ancient globular star cluster so dense and crowded that individual stars can not be distinguished in its closely packed core. An…
Strange Orange Soil on the Moon
How did orange soil appear on the Moon? This mystery began when astronaut Harrison Schmidt noticed the off-color patch near Apollo 17 's Taurus-Littrow landing site in 1972.…
Spiral Galaxy NGC 1232
Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232 , captured in detail by one of the new Very Large Telescopes , is a…
Another Comet LINEAR Breaks Up
Last year, a different comet LINEAR (C/1999 S4) broke up. This year, a comet first imaged by the Lincoln Near Asteroid Research (LINEAR) telescope in New Mexico on 2001 January 3,…
Sagittarius Star Cloud
Stars come in all different colors. The color of a star indicates its surface temperature , an important property used to assign each star a spectral type . Most stars in the…
Damage to Apollo 13
In April of 1970 , after an oxygen tank exploded and crippled their service module, the Apollo 13 astronauts were forced to abandon plans to make the third human lunar landing .…
HD 82943: Planet Swallower
Stars like HD 82943 are main sequence G dwarf stars with temperatures and compositions similar to the Sun . Also like the Sun, HD 82943 is known to have at least two giant planets…
Solar Neutrino Astronomy
Neutrinos are subatomic particles generated by the nuclear reactions which power stars like our Sun . Flying outward from the Sun's core, they easily pass through the Sun (and…
The Center of the Circinus Galaxy in X-Rays
Are black holes the cause of X-rays that pour out from the center of the Circinus galaxy ? A new high-resolution image from the orbiting Chandra X-ray Observatory has resolved the…
A Radar Image of Venus
The largest radio telescopes in the world are working together to create a new map of the surface of Venus. The surface of Venus is unusually hidden by a thick atmosphere of…
A Cerro Tololo Sky
High atop a Chilean mountain lies one of the premier observatories of the southern sky: Cerro Tololo . Pictured above is one of the premier telescopes of the Cerro Tololo…
Crater Copernicus
One of the more prominent craters on the Moon is named Copernicus . Copernicus is a large young crater visible with binoculars slightly northwest of the center of the Moon's…
Shuttle Moon
As a gorgeous full Moon rose above the eastern horizon on February 7, the Space Shuttle Atlantis streaked skyward towards an orbital rendezvous with the International Space…
X-Ray Rainbows
A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors . In order of increasing energy, the well known spectrum of colors in a rainbow runs…
Viewing discoveries from 3 June 2001 through 11 May 2001.