Remembering NEOWISE
31.07.2021

It was just last July. If you could see the stars of the Big Dipper, you could find Comet NEOWISE in your evening sky. After sunset denizens of the north could look for the naked-eye comet below the bowl of that famous celestial kitchen utensil and above the northwestern horizon.

APOD: 2026 April 29 Б The Moon, Venus, and the Pleiades
29.04.2026

No, Earth did not recently acquire six more moons! TodayБs APOD is a combination of images following the Moon, Venus, and the Pleiades across a southern Sicilian sky as twilight turned to evening on April 19.

Helios Helium
20.01.2001

This image of the active Sun was made using ultraviolet light emitted by ionized Helium atoms in the Solar chromosphere. Helium was first discovered in the Sun in 1868, its name fittingly derived from from the Greek word Helios, meaning Sun. Credit for the discovery goes to astronomer Joseph Norman Lockyer (born May 17, 1836).

The Solar Spectrum
15.08.2000

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Local Interstellar Cloud
10.02.2002

The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun.

Blue Jet Lightning
12.11.1995

Recently two new types of lightning have been verified: red sprites and blue jets. These atmospheric discharges occur very high in the Earth's atmosphere - much higher than the familiar form of lightning. Blue jets appear blue in color and go from the tops of clouds to a height of about 50 kilometers.

A High Energy Fleet
25.02.1996

Looking like a fleet of futuristic starcruisers poised over planet Earth, NASA's highly successful series of High Energy Astrophysical Observatory (HEAO) spacecraft appear above in a vintage illustration. Labeled A, B, and C in this conceptual picture, the spacebased telescopes were known as HEAO-1, HEAO-2, and HEAO-3 respectively.

Io Volcano Culann Patera
18.12.2002

What causes the unusual colors surrounding Io's volcanoes? Io, the innermost large moon of Jupiter, is known to be the most tumultuous body in the Solar System. Approximately the size of Earth...

Io Shadow
23.04.1999

Orbiting Jupiter once every 43 hours, the volcanic moon Io cruises 500,000 kilometers above swirling, banded cloud-tops. Orbiting Earth once every 1.5 hours, the Hubble Space Telescope watched as Io accompanied by its shadow crossed the face of the reigning gas giant planet in 1997.

The First Rocket Launch from Cape Canaveral
4.06.2006

A new chapter in space flight began on 1950 July with the launch of the first rocket from Cape Canaveral, Florida: the Bumper 2. Shown above, the Bumper 2 was an ambitious two-stage rocket program that topped a V-2 missile base with a WAC Corporal rocket.