Since the “space age” has started in the early 1960s, astronauts have taken more than 1.8 million photographs of the Earth from orbit, and about one-third of them (approximately 600,000) have been taken at night. But they don’t always know what they are looking at. You can help, announced NASA.
Category Archives: Space Exploration
Krakatoa, from space
On August 26-27, 1883, a small island in the Indian Ocean obliterated itself in one the most notorious volcanic eruptions in history. Krakatau (often spelled Krakatoa) erupted with such violence that two-thirds of the island, about 23 square kilometers, sank into the Sunda Strait. The explosions heard in the 1883 eruption remain the loudest noise on human record. The sound was heard across the Indian Ocean, as far away as Rodriguez Island, 4,653 kilometers (2,891 miles) to the west, and Australia, 3,450 kilometers (2,144 miles) to the east. The massive eruption also generated a series of tsunamis, which produced waves as high as 30 meters (98 feet) tall.
Will We Ever Visit Other Stars?
The Earth is our one and only home. As Carl Sagan said (Pale Blue Dot: A Vision of the Human Future in Space), “On Earth, everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”.
But will we ever leave our home and visit other stars in the future?
Our galaxy, “The Milky Way” is a barred spiral galaxy (a spiral galaxy with a central bar-shaped structure composed of stars) some 100,000-120,000 light-years in diameter, which contains 100-400 billion stars. It may contain at least as many planets as well. Our Sun (the Solar System) is located within the disk, about 27,000 light-years away from the Galactic Center, on the inner edge of one of the spiral-shaped concentrations of gas and dust called the Orion Arm.
Great supermoon photos by Russian Cosmonaut
August 10, 2014
Pale Blue Dot
The farthest spacecraft from Earth, NASA’s Voyager 1 Notes 1 probe took a photo of planet Earth in 1990, from a record distance of about 6 billion kilometers (3.7 billion miles, 40 AU) from Earth. The photo is known as the Pale Blue Dot. In the photograph, Earth is shown as a fraction of a pixel (0.12 pixel in size) against the vastness of space. It was a part of the solar system Family Portrait series of images.
The Voyager 1 spacecraft, which had completed its primary mission and was leaving the Solar System, was commanded by NASA to turn its camera around and to take a photograph of Earth across a great expanse of space, at the request of Carl Sagan Notes 2.
