“The fact that none of these asteroid impacts shown in the video was detected in advance is proof that the only thing preventing a catastrophe from a ‘city-killer’ sized asteroid is blind luck.”

- Ed Lu, B612 Foundation CEO and former NASA astronaut

When we think of recent large asteroid impacts on Earth, only a handful may come to mind. In particular, one is the forest-flattening 1908 Tunguska explosion over Siberia (which may have been the result of a comet) and another is the February 2013 meteor that exploded over Chelyabinsk, shattering windows with its air blast. Both occurred in Russia, the largest country on Earth, and had human witnesses — in the case of the latter many witnesses thanks to today’s ubiquitous dashboard cameras.

While it’s true that those two observed events took place 105 years apart, there have been many, many more large-scale asteroid impacts around the world that people have not witnessed, if only due to their remote locations… impact events that, if they or ones like them ever occurred above a city or populated area, could result in destruction of property, injuries to people, or worse.

(And these are only the ones we’ve found out about over the past 13 years.) [click to continue…]

Views of Earth From Space on Earth Day 2014

by Nancy Atkinson on April 22, 2014

NOAA's GOES-East satellite captured this stunning view of the Americas on Earth Day, April 22, 2014 at 11:45 UTC/7:45 a.m. EDT. The data from GOES-East was made into an image by the NASA/NOAA GOES Project at NASA's Goddard Space Flight Center. Credit: NASA/NOAA.

NOAA’s GOES-East satellite captured this stunning view of the Americas on Earth Day, April 22, 2014 at 11:45 UTC/7:45 a.m. EDT. The data from GOES-East was made into an image by the NASA/NOAA GOES Project at NASA’s Goddard Space Flight Center. Credit: NASA/NOAA.

It’s been said that one of the reasons Earth Day was started back in 1970 was because of the images of Earth from space taken during the Apollo missions to the Moon. So, what better way to celebrate than to see how Earth looks today from space?

NOAA’s GOES-East satellite captured this stunning view of the Americas on Earth Day, April 22, 2014 at 11:45 UTC/7:45 a.m. EDT.
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John Houbolt demonstrating Lunar Orbit Rendezvous circa 1962. Credit: NASA.

John Houbolt demonstrating Lunar Orbit Rendezvous circa 1962. Credit: NASA.

The space community lost a colossus of the of the Apollo era last week, when John Houbolt passed away last Tuesday just five days after his 95th birthday.

Perhaps the name isn’t as familiar to many as Armstrong or Von Braun, but John Houbolt was a pivotal figure in getting us to the Moon. [click to continue…]

How Many Moons Does Venus Have?

by Elizabeth Howell on April 22, 2014

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL

There are dozens upon dozens of moons in the Solar System, ranging from airless worlds like Earth’s Moon to those with an atmosphere (most notably, Saturn’s Titan). Jupiter and Saturn have many moons each, and even Mars has a couple of small asteroid-like ones. But what about Venus, the planet that for a while, astronomers thought about as Earth’s twin?

The answer is no moons at all. That’s right, Venus (and the planet Mercury) are the only two planets that don’t have a single natural moon orbiting them. Figuring out why is one question keeping astronomers busy as they study the Solar System.

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How Far Is A Light Year in Miles Or Kilometers?

by Elizabeth Howell on April 22, 2014

The NASA/ESA Hubble Space Telescope has captured this vivid image of spiral galaxy Messier 77 — a galaxy in the constellation of Cetus, some 45 million light-years away from us. The streaks of red and blue in the image highlight pockets of star formation along the pinwheeling arms, with dark dust lanes stretching across the galaxy’s starry centre. The galaxy belongs to a class of galaxies known as Seyfert galaxies, which have highly ionised gas surrounding an intensely active centre. Credit: NASA, ESA & A. van der Hoeven

The NASA/ESA Hubble Space Telescope has captured this vivid image of spiral galaxy Messier 77 — a galaxy in the constellation of Cetus, some 45 million light-years away from us. The streaks of red and blue in the image highlight pockets of star formation along the pinwheeling arms, with dark dust lanes stretching across the galaxy’s starry centre. The galaxy belongs to a class of galaxies known as Seyfert galaxies, which have highly ionised gas surrounding an intensely active centre. Credit: NASA, ESA & A. van der Hoeven

We hope you have a big suitcase if you’re planning a trip across the cosmos. At the speed of light — a speed that no technology yet can achieve — it would take you about four years to get to the Alpha Centauri star system, the nearest group to our own. Zipping to the nearest galaxy, the Canis Major Dwarf Galaxy, would take you about 25,000 light-years.

As the phrase “light year” implies, that’s the distance that light travels in a year. It’s as fast as anything can travel, at least as best as we can understand it. Sometimes referred to as a “cosmic speed limit“, going as fast as light (or even faster) is impossible for a physical object, according to Albert Einstein’s measurements a century ago. As you get faster and faster, he showed, your mass increases to infinity. But there’s still discussion around that.

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