Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

February 25, 1996
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A High Energy Fleet
Credit: NASA, MSFC Historical Archive.

Explanation: 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. HEAO-1 and HEAO-2 were responsible for revealing to earthlings the wonders of the x-ray sky, discovering 1,000s of celestial sources of high-energy radiation. HEAO-2, also known as the Einstein Observatory, was launched near the date of the famous physicist's 100th birthday (November of 1978) and was the first large, fully imaging x-ray telescope in space. HEAO-3, the last in the series, was launched in 1979 and measured high energy cosmic-ray particles and gamma-rays.

Tomorrow's picture: Fireball!


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Authors & editors: Robert Nemiroff (GMU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
A service of: LHEA at NASA/ GSFC