Happy Earth Day! Here is a new time-lapse of images from the International Space Station, titled The World Outside My Window. You may not be looking at it from this perspective, but you’ve got a world outside your window, too. Take care of it.
Turn up your speakers, go full screen, and lean back. Heck … this one even goes to 4K. Enjoy.
(video by David Peterson)
Earth rise on the Moon
On December 24, 1968, Apollo 8 astronauts Frank Borman, James Lovell, and William Anders were coming around from the far side of the Moon on their fourth orbit. Borman began to roll the spacecraft, and as he did, the Earth rose into view over the Moon’s limb. Anders, photographing the Moon from the right side window, caught sight of the view, and exclaimed: “Oh my God, look at that picture over there! There’s the Earth comin’ up. Wow, is that pretty!”
He snapped a black and white photo (bottom), capturing humanity’s first view of Earth from another planetary body. A few minutes later, Anders put color film in the camera and took the iconic color photographs of a half Earth hanging over the lunar horizon.
Credit: NASA/Earth Observatory
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Today’s NPRchives comes from NPR Librarian Janel Kinlaw, who writes:
Earth Day, April 22, was started in 1970 channeling the energy of the anti-war protests from the previous decade. On the 15th anniversary in 1985, Noah Adams interviewed Alden Meyer, who at the time was the executive director of Environmental Action the founding organization of Earth Day. Here’s how Mr. Meyer described the first celebration:
“It was so big that it got away from the organizers here in Washington. They didn’t know half of what was going on until weeks after the event April 22 – the reports started trickling back just how big it had been. They were just overwhelmed on how the thing just organized itself.”
10 Planetary Facts for Earth Day 2014
Astronomer Phil Plait has put together some fun facts about our planet in honor of today’s Earth Day, such as, “What does the Earth have that no other planet we know of has? A lot of water on the surface - nearly a third of the planet.”
Read more at Slate - and Happy Earth Day!
The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005. Several hundred images, taken with the wide-angle camera in MESSENGER’s Mercury Dual Imaging System (MDIS), were sequenced into a movie documenting the view from MESSENGER as it departed Earth.
Comprising 358 frames taken over 24 hours, the movie follows Earth through one complete rotation. The spacecraft was 40,761 miles (65,598 kilometers) above South America when the camera started rolling on Aug. 2. It was 270,847 miles (435,885 kilometers) away from Earth - farther than the Moon’s orbit - when it snapped the last image on Aug. 3.
"Now, for the first time in its billions of years of history, our planet is protected by far-seeing sentinels, able to anticipate danger from the distant future – a comet on a collision course, or global warming–and devise schemes for doing something about it. The planet has finally grown its own nervous system: us."
Asteroid Impacts on Earth More Powerful than Nuclear Bomb
Between 2000 and 2013, 26 explosions ranging from 1-600 kilotons have been detected by the Nuclear Test Ban Treaty Organization’s network of sensors. The bomb that decimated Hiroshima had an energy equivalent of 15 kilotons.
Anonymous asked: I feel a bit stupid asking this... But what's in the center of a galaxy ?
First off, not a stupid question at all! In fact, it is a very good one that many astronomers have dedicated their lives to researching! I think I’ll start with our galaxy and the general case of galaxies.
Here is an image of the center of our milky way (we can only get this side-on view because we are viewing it from within):
In this photo, a supermassive black hole resides in the bright white area, right of the center. The black hole has been calculated to be about 4 million solar masses. Yes. You heard correctly, there is a supermassive black hole at the center of our galaxy. However, don’t panic.
The supermassive black hole is about 27 kilolightyears away and we are a long way from any harm it could cause us. This is actually a very normal thing about the universe we live in. It is theorized that there are supermassive black holes at the center of almost every large galaxy! Everywhere we look we find evidence of them in the orbits of stars around the centers of galaxies.
Some galaxies have special cases of black holes, known as quasars, at their center. Here is an artists impression of a quasar:
Quasar’s and supermassive black holes, when viewed relative to galaxies, are members of objects known as active galactic nucleus (or AGN for short). AGN’s are the super dense regions at the center of galaxies that have abnormal luminosity (meaning they are super bright), and often emit light/radiation in all wavelengths of the electromagnetic spectrum. Galaxies with AGN’s are known as Active Galaxies. Our galaxy is considered an active Galaxy.
Here is a hubble image of an AGN at the center of Galaxy M87. Electromagnetic radiation is seen being emitted from a jet:
There is still very little known about the causes of these AGN’s, how they are formed from supermassive black holes and the intermediate stages of AGN’s and black holes. There are even galaxies that have no AGN’s and the stability of galaxies has been a big mystery for the past few years. There is still much that we can learn in this area.
Science doesn’t have all of the answers, and it may never have all of them. But Science has a way to figure out those answers. Someone once told me that younger scientists are able to make breakthrough discoveries because they don’t yet know what is impossible.
So I would like to tell you again, this was not a dumb question! I encourage you to continue to ask these questions! Thanks for the great ask.
"To find the truth, we need imagination and skepticism" - Carl Sagan, Cosmos: A Personal Voyage