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NASA // Public Domain

On This Day in 1962, NASA Launched and Destroyed Mariner 1

NASA // Public Domain
NASA // Public Domain

On July 22, 1962, NASA launched the Mariner 1 probe, which was intended to fly by Venus and collect data on its temperature and atmosphere. It was intended to be the first interplanetary craft—the first time humans had sent a space probe to another world. Unfortunately, NASA aborted the mission 293 seconds after launch, destroying the probe in the Atlantic. What happened?

First off, a bit of history. Mariner 1 was based on the pre-existing Block 1 craft used in the Ranger program, which was aimed at gathering data on our moon. Those early Ranger probes didn't do so well—both Ranger 1 and Ranger 2 suffered early failures in orbit. Mariner 1 was a modified version of the Ranger design, intended for a much longer mission to another planet. It lacked a camera, but had various radiometers, a cosmic dust detector, and a plasma spectrometer—it would be capable of gathering data about Venus, but not pictures per se.

The two previous Ranger missions had used basically the same launch system, so it was reasonably well-tested. The Ranger probes had made it into orbit, but had been unable to stabilize themselves after that.

Mariner 1 launched on the evening of July 22, 1963. Its Atlas-Agena rocket was aided by two radar systems, designed to track data on velocity (the "Rate System") and distance/angle (the "Track System") and send it to ground-based computers. By combining that data, the computers at Cape Canaveral helped the rocket maintain a trajectory that, when separated, would lead Mariner 1 to Venus.

Part of the problem involved in handling two separate radars was that there was a slight delay—43 milliseconds—between the two radars' data reports. That wasn't a problem by itself. The Cape computer simply had to correct for that difference. But in that correction process, a problem was hiding—a problem that hadn't appeared in either of the previous Ranger launches.

To correct the timing of the data from the Rate System—the radar responsible for measuring velocity of the rocket—the ground computer ran data through a formula. Unfortunately, when that formula had been input into the computer, a crucial element called an overbar was omitted. The overbar indicated that several values in the formula belonged together; leaving it out meant that a slightly different calculation would be made. But that wasn't a problem by itself.

The fate of Mariner 1 was sealed when the Rate System hardware failed on launch. This should not have been a fatal blow, as the Track System was still working, and Ground Control should have been able to compensate. But because that overbar was missing, calculations on the incoming radar data went wonky. The computer incorrectly began compensating for normal movement of the spacecraft, using slightly incorrect math. The craft was moving as normal, but the formula for analyzing that data had a typo—so it began telling Mariner 1 to adjust its trajectory. It was fixing a problem that didn't exist, all because a few symbols in a formula weren't grouped together properly.

Mariner 1's rocket did as it was told, altering its trajectory based on faulty computer instructions. Looking on in horror, the Range Safety Officer at the Cape saw that the Atlas rocket was now headed for a crash-landing, potentially either in shipping lanes or inhabited areas of Earth. It was 293 seconds after launch, and the rocket was about to separate from the probe.

With just 6 seconds remaining before the Mariner 1 probe was scheduled to separate (and ground control would be lost), that officer made the right call—he sent the destruct command, ditching Mariner I in an unpopulated area of the Atlantic.

The incident was one of many early space launch failures, but what made it so notable was the frenzy of reporting about it, mostly centered on what writer Arthur C. Clarke called "the most expensive hyphen in history." The New York Times incorrectly reported that the overbar was a "hyphen" (a reasonable mistake, given that they are both printed horizontal lines) but correctly reported that this programming error, when coupled with the hardware failure of the Rate System, caused the failure. The bug was identified and fixed rapidly, though the failed launch cost $18,500,000 in 1962 dollars—north of $150 million today.

Fortunately for NASA, Mariner 2 was waiting in the wings. An identical craft, it launched just five weeks later on August 27, 1962. And, without the bug and the radar hardware failure, it worked as planned, reaching Venus and becoming the first interplanetary spacecraft in history. It returned valuable data about the temperature and atmosphere of Venus, as well as recording solar wind and interplanetary dust data along the way. There would be 10 Mariner missions in all [PDF], with Mariner 1, 3, and 8 suffering losses during launch.

For further reading, consult this Ars Technica discussion, which includes valuable quotes from Paul E. Ceruzzi's book Beyond The Limits—Flight Enters the Computer Age.

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Look Up! Residents of Maine and Michigan Might Catch a Glimpse of the Northern Lights Tonight
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iStock

The aurora borealis, a celestial show usually reserved for spectators near the arctic circle, could potentially appear over parts of the continental U.S. on the night of February 15. As Newsweek reports, a solar storm is on track to illuminate the skies above Maine and Michigan.

The Northern Lights (and the Southern Lights) are caused by electrons from the sun colliding with gases in the Earth’s atmosphere. The solar particles transfer some of their energy to oxygen and nitrogen molecules on contact, and as these excited molecules settle back to their normal states they release light particles. The results are glowing waves of blue, green, purple, and pink light creating a spectacle for viewers on Earth.

The more solar particles pelt the atmosphere, the more vivid these lights become. Following a moderate solar flare that burst from the sun on Monday, the NOAA Space Weather Prediction Center forecast a solar light show for tonight. While the Northern Lights are most visible from higher latitudes where the planet’s magnetic field is strongest, northern states are occasionally treated to a view. This is because the magnetic North Pole is closer to the U.S. than the geographic North Pole.

This Thursday night into Friday morning is expected to be one of those occasions. To catch a glimpse of the phenomena from your backyard, wait for the sun to go down and look toward the sky. People living in places with little cloud cover and light pollution will have the best chance of spotting it.

[h/t Newsweek]

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10 Facts About the Dwarf Planet Haumea
Kevin Gill, Flickr // CC BY-2.0
Kevin Gill, Flickr // CC BY-2.0

In terms of sheer weirdness, few objects in the solar system can compete with the dwarf planet Haumea. It has a strange shape, unusual brightness, two moons, and a wild rotation. Its unique features, however, can tell astronomers a lot about the formation of the solar system and the chaotic early years that characterized it. Here are a few things you need to know about Haumea, the tiny world beyond Neptune.

1. THREE HAUMEAS COULD FIT SIDE BY SIDE IN EARTH.

Haumea is a trans-Neptunian object; its orbit, in other words, is beyond that of the farthest ice giant in the solar system. Its discovery was reported to the International Astronomical Union in 2005, and its status as a dwarf planet—the fifth, after Ceres, Eris, Makemake, and Pluto—was made official three years later. Dwarf planets have the mass of a planet and have achieved hydrostatic equilibrium (i.e., they're round), but have not "cleared their neighborhoods" (meaning their gravity is not dominant in their orbit). Haumea is notable for the large amount of water ice on its surface, and for its size: Only Pluto and Eris are larger in the trans-Neptunian region, and Pluto only slightly, with a 1475-mile diameter versus Haumea's 1442-mile diameter. That means three Haumeas could fit sit by side in Earth—and yet it only has 1/1400th of the mass of our planet.

2. HAUMEA'S DISCOVERY WAS CONTROVERSIAL.

There is some disagreement over who discovered Haumea. A team of astronomers at the Sierra Nevada Observatory in Spain first reported its discovery to the Minor Planet Center of the International Astronomical Union on July 27, 2005. A team led by Mike Brown from the Palomar Observatory in California had discovered the object earlier, but had not reported their results, waiting to develop the science and present it at a conference. They later discovered that their files had been accessed by the Spanish team the night before the announcement was made. The Spanish team says that, yes, they did run across those files, having found them in a Google search before making their report to the Minor Planet Center, but that it was happenstance—the result of due diligence to make sure the object had never been reported. In the end, the IAU gave credit for the discovery to the Spanish team—but used the name proposed by the Caltech team.

3. IT'S NAMED FOR A HAWAIIAN GODDESS.

In Hawaiian mythology, Haumea is the goddess of fertility and childbirth. The name was proposed by the astronomers at Caltech to honor the place where Haumea's moon was discovered: the Keck Observatory on Mauna Kea, Hawaii. Its moons—Hi'iaka and Namaka—are named for two of Haumea's children.

4. HAUMEA HAS RINGS—AND THAT'S STRANGE.

Haumea is the farthest known object in the solar system to possess a ring system. This discovery was recently published in the journal Nature. But why does it have rings? And how? "It is not entirely clear to us yet," says lead author Jose-Luis Ortiz, a researcher at the Institute of Astrophysics of Andalusia and leader of the Spanish team of astronomers who discovered Haumea.

5. HAUMEA'S SURFACE IS EXTREMELY BRIGHT.

In addition to being extremely fast, oddly shaped, and ringed, Haumea is very bright. This brightness is a result of the dwarf planet's composition. On the inside, it's rocky. On the outside, it is covered by a thin film of crystalline water ice [PDF]—the same kind of ice that's in your freezer. That gives Haumea a high albedo, or reflectiveness. It's about as bright as a snow-covered frozen lake on a sunny day.

6. HAUMEA HAS ONE OF THE SHORTEST DAYS IN THE ENTIRE SOLAR SYSTEM.

If you lived to be a year old on Haumea, you would be 284 years old back on Earth. And if you think a Haumean year is unusual, that's nothing next to the length of a Haumean day. It takes 3.9 hours for Haumea to make a full rotation, which means it has by far the fastest spin, and thus shortest day, of any object in the solar system larger than 62 miles.

7. HAUMEA'S HIGH SPEED SQUISHES IT INTO A SHAPE LIKE A RUGBY BALL.

haumea rotation gif
Stephanie Hoover, Wikipedia // Public Domain

As a result of this tornadic rotation, Haumea has an odd shape; its speed compresses it so much that rather than taking a spherical, soccer ball shape, it is flattened and elongated into looking something like a rugby ball.

8. HIGH-SPEED COLLISIONS MAY EXPLAIN HAUMEA'S TWO MOONS.

Ortiz says there are several mechanisms that can have led to rings around the dwarf planet: "One of our favorite scenarios has to do with collisions on Haumea, which can release material from the surface and send it to orbit." Part of the material that remains closer to Haumea can form a ring, and material further away can help form moons. "Because Haumea spins so quickly," Ortiz adds, "it is also possible that material is shed from the surface due to the centrifugal force, or maybe small collisions can trigger ejections of mass. This can also give rise to a ring and moons."

9. ONE MOON HAS WATER ICE—JUST LIKE HAUMEA.

Ortiz says that while the rings haven't transformed scientists' understanding of Haumea, they have clarified the orbit of its largest moon, Hi'iaka—it is equatorial, meaning it circles around Haumea's equator. Hi'iaka is notable for the crystalline water ice on its surface, similar to that on its parent body.

10. TRYING TO SEE HAUMEA FROM EARTH IS LIKE TRYING TO LOOK AT A COIN MORE THAN 100 MILES AWAY.

It's not easy to study Haumea. The dwarf planet, and other objects at that distance from the Sun, are indiscernible to all but the largest telescopes. One technique used by astronomers to study such objects is called "stellar occultation," in which the object is observed as it crosses in front of a star, causing the star to temporarily dim. (This is how exoplanets—those planets orbiting other stars—are also often located and studied.) This technique doesn't always work for objects beyond the orbit of Neptune, however; astronomers must know the objects' orbits and the position of the would-be eclipsed stars to astounding levels of accuracy, which is not always the case. Moreover, Ortiz says, their sizes are oftentimes very small, "comparable to the size of a small coin viewed at a distance of a couple hundred kilometers."

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