Astronomy Picture of the Day

1998-07-26 AAO

Antares is a huge star. In a class called red supergiant, Antares is about 700 times the diameter of our own Sun, 15 times more massive, and 10,000 times brighter. Antares is the brightest star in the constellation of Scorpius and one of the ...

1998-07-25

Aloha! With the graceful arc of the Earth's limb in the background, the Hawaiian Island archipelago is visible in this stunning photo taken by the astronauts onboard the shuttle Discovery in October of 1988. Along with popular beaches and ...

1998-07-24

On another Friday (May 5, 1961), at the dawn of the space age, NASA controllers "lit the candle" and sent Alan B. Shepard Jr. arcing into space atop a Redstone rocket. The picture shows the pressure-suited Shepard before the launch in his cramped ...

1998-07-23

This dramatic artist's vision shows a city-sized neutron star centered in a disk of hot plasma drawn from its enfeebled red companion star. Ravenously accreting material from the disk, the neutron star spins faster and faster emitting powerful ...

1998-07-22

Ganymede has craters within craters within craters. The old surface of the largest moon in the Solar System shows its age by the large amount of these impact features. The above picture released last week shows two old craters with dark floors ...

1998-07-21 D. Malin

M33 is a prominent nearby spiral galaxy. Nicknamed the Triangulum, M33 is one of the larger members of the Local Group of Galaxies. Two massive spiral galaxies dominate the Local Group: M31 and our Milky Way Galaxy. M33 is the only other ...

1998-07-20

Goodbye El Ni?o. Hello La Ni?a? Scientists are watching to see if an evolving pool of relatively cool water in the mid-Pacific Ocean will develop into a full "La Ni?a". Over the past several months, the water temperature in the Equatorial ...

1998-07-19 CfA

This huge ball of stars predates our Sun. Long before mankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 250 or so globular clusters that ...

1998-07-18

Robert H. Goddard, one of the founding fathers of modern rocketry, was born in Worcester Massachusetts in 1882. As a 16 year old, Goddard read H.G. Wells' science fiction classic "War Of The Worlds" and dreamed of spaceflight. By 1926 he had ...

1998-07-17 R. Scott

Comets are cosmic icebergs. They follow very elongated orbits which carry them from the frozen, remote outer reaches of the Solar System to close encounters with the Sun. Heated by sunlight, they slough off layers of material as gas and dust, ...