Blog Archives

Our Five-Trillion-Mile Close Call: the Star(s) That Skimmed the Solar System

Artist's rendering of two stars that made a close pass by the Sun 70,000 years ago. (Michael Osadciw/University of Rochester)

Artist’s rendering of two stars, a red dwarf and a brown dwarf, that made a close pass by the Sun 70,000 years ago. (Michael Osadciw/University of Rochester)

It’s like something out of a Hollywood film or a science fiction novel: a dark star sneaks up on Earth from just outside the Solar System, discovered too late to do anything about it (and really, what could we do?) and plows through the cloud of comets that surrounds the Sun like a haze of icy gnats, sending them flying everywhere… including on collision courses with Earth. Mass hysteria ensues.

Except that this isn’t just a story concept – scientists think this is actually something that happened 70,000 years ago! Minus the mass hysteria, of course… our ancestors were just beginning to settle down in the fertile lands of the Middle East after wandering out of Africa and would have had no idea what was happening at the edges of the Solar System (besides maybe a bright star occasionally flaring up in the night sky.)

Read the rest of this entry

Watch This Stunning Seamless Video of Earth From Orbit

Recently featured on Universe Today, this video of Earth from space assembled by video artist Phil Selmes uses actual photos captured from the Space Station, with some fancy editing to create seamless transitions between views. It’s another beautiful presentation of the fragile oasis we call home.

“I don’t see politics, races, borders, countries, religions or differences,” Selmes said in an article on Universe Today. “I saw one planet, one world, one incredibly beautiful miracle in the absolute vastness of the universe.”

See more of Selmes’ work on his YouTube channel. 

Voyager’s Valentine Turns 25 Today

If you’re in love with space exploration then you’ll fall for this: it’s the picture of Earth taken from the Voyager 1 spacecraft after it passed the orbit of Pluto in 1990. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, and reminds us that we are all just floating on “a mote of dust suspended in a sunbeam.”

This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which I don’t think will ever happen.)

Venus, Earth, Jupiter, Saturn, Uranus and Neptune as seen by Voyager 1 in 1990 (Credit: NASA)

On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.

From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space.

“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”

– Carl Sagan

Read the rest of this entry

The First Human Satellite: Flying Free With the MMU

NASA astronaut Bruce McCandless II during his flight test of the Manned Maneuvering Unit (MMU) in  February 1984 (NASA)

NASA astronaut Bruce McCandless II during his flight test of the Manned Maneuvering Unit (MMU) in February 1984 (NASA)

31 years ago today, on Feb. 7, 1984, NASA astronaut Bruce McCandless II became the first “human satellite” when he tested the Manned Maneuvering Unit during STS-41B. Self-propelled via 24 small nitrogen-powered thrusters, the MMU allowed McCandless (who was instrumental in developing the Unit at Lockheed Martin) to travel tether-free through space. In the iconic photo above McCandless is seen hovering against the blackness of space, 320 feet (98 meters) away from the Challenger orbiter.

A former U.S. Navy captain, McCandless was 46 years old when he performed his historic tether-free flight.

“May well have been one small step for Neil, but it’s a heck of a big leap for me!”
– STS-41B Mission Specialist Bruce McCandless II, Feb. 7, 1984

Read the rest of this entry

The First Christmas From the Moon

“We came all this way to explore the Moon, and the most important thing is that we discovered the Earth.”
– Bill Anders, Apollo 8

"Earthrise" from Apollo 8, December 24, 1968 (NASA)

“Earthrise” from Apollo 8, December 24, 1968 (NASA)

On Christmas Eve 46 years ago, December 24, 1968, the Apollo 8 astronauts entered orbit around the Moon and came upon an amazing sight: a blue Earth “rising*” beyond the tan-grey desolation of the lunar surface. Commander Frank Borman spotted the scene first was able to rotate the Command Module so Earth remained in view through the small windows, while CM pilot Jim Lovell snapped this photograph onto a roll of color film that Lunar Module Pilot Bill Anders was able to quickly locate for him. It was the first time humans saw the Earth from the Moon in person, and it was also the first Christmas astronauts spent in space.

“The vast loneliness is awe-inspiring and it makes you realize just what you have back there on Earth,” Jim Lovell said.

Read the rest of this entry

Oxygen Isotopes Support Our Moon’s Violent Origin

The "Giant Impact" hypothesis has the Moon formed from an impact between early Earth and a Mars-sized body (NASA)

The “Giant Impact” hypothesis has the Moon formed from an impact between early Earth and a Mars-sized body (NASA)

While it may not be a true “smoking gun” (there have been four and a half billion years of cooling off, after all!) scientists in Germany have found further support for the currently accepted scenario of the origin of our Moon, based on chemical analysis of rocks brought back by Apollo astronauts. (And yes, we really went to the Moon.)

Read the rest of this entry


Get every new post delivered to your Inbox.

Join 19,828 other followers

%d bloggers like this: