Two decades before astronauts walked on the Moon, American movie-goers got a good preview of what the trip might look like. “Destination Moon” was the first big space movie. And it was the first to accurately explain the science and engineering of a trip to the Moon.
Co-written by science-fiction author Robert Heinlein, the movie premiered 75 years ago today. In the story, millionaire businessmen decide to finance a lunar voyage. They build a nuclear-powered rocket in the desert, then send it on its way. Problems ensue, but the crew lands on the Moon and makes it back home safely.
The backers are convinced in part by a short cartoon that accurately explained how rockets work. In fact, the cartoon was so good that NASA later used a revised version to explain rockets to the public.
Destination Moon also showed the effects of acceleration and zero-gravity. During a spacewalk, one of the crew maneuvered using a tank of oxygen; the first real American spacewalker used a similar technique. And on the Moon, the crew loped along just like the Apollo astronauts.
The film didn’t get everything right. The landscape – painted by space artist Chesley Bonestell – was too sharp and craggy. And the art director added cracks to the surface like those in a dry riverbed to add a feeling of depth.
Still, Destination Moon remains one of the most accurate movies about spaceflight – a fantastic trip to the Moon long before the real thing.
Script by Damond Benningfield
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Moon and Mercury
Early in its history, the inner solar system was chaotic. Violent collisions might have destroyed many small worlds, while perhaps creating others – including the Moon. It probably formed when a planet as big as Mars rammed into Earth, blasting out debris that came together to make the Moon.
A recent study says that a meteorite discovered a few years ago might be a remnant of one of the demolished worlds.
NWA 15915 was discovered in Algeria. Scientists analyzed the composition, structure, and magnetic properties of the six-pound meteorite. They concluded that it’s a rare type of meteorite – it doesn’t come from any known asteroid, planet, or moon.
But it does have some similarities to Mercury, the smallest planet and the one closest to the Sun. The study suggests that NWA 15915 might have come from a Mercury-like planet born in the same region of the solar system. The planet was demolished long ago by a giant impact. But a few fragments remain.
The findings are preliminary. So it’ll take more work to confirm that a piece of a dead planet fell atop the desert sands of northwestern Africa.
Mercury itself is near the Moon this evening. It looks like a fairly bright star to the left of the Moon. They’re quite low in the sky as twilight fades, so you need a clear horizon to spot them.
Script by Damond Benningfield
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2:19
Cygnus X-3
It would be fascinating to get close to Cygnus X-3. Unfortunately, it also would be deadly. The system is bathed in X-rays and ultraviolet radiation. It features powerful “jets” that blast into space like energy cannons. And it probably has a black hole – a one-way trip to oblivion.
Cygnus X-3 is in the swan, which swoops across the eastern sky on these early summer evenings. The system itself is too faint to see. In fact, we can’t see its visible light even with the largest telescopes because it’s hidden behind thick clouds of dust.
But we can see it in other wavelengths, including X-rays, gamma rays, and radio waves. Those forms of energy have allowed astronomers to piece together the system’s likely story.
Cygnus X-3 probably consists of a black hole plus a brilliant companion. The companion probably is a dozen or more times the Sun’s mass, and a couple of hundred thousand times its brightness.
The bright star is blowing huge amounts of gas into space. The black hole grabs some of the gas, which forms a spinning disk around the black hole. Some of the gas is funneled into high-speed jets that fire into space. One of those jets is aimed almost directly at Earth.
The brilliant companion star is likely to explode in the next million years or so, with its core collapsing to form another black hole. But the blast might rip the system apart – perhaps causing Cygnus X-3 to fade away.
Script by Damond Benningfield
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2:19
P Cygni
425 years ago, a “new” star flared to life near the neck of Cygnus, the swan. The star slowly faded, then flared twice more during the 17th century. It’s remained visible ever since. And someday soon, it’ll flare up again – for the last time: It’ll explode as a supernova.
P Cygni is more than 5,000 light-years away, so it must be extremely bright for us to see it at all. And in fact, it’s one of the brightest stars in the entire galaxy – 600 thousand times brighter than the Sun.
P Cygni is so brilliant because it’s 35 to 40 times the mass of the Sun. Such a monster burns through the nuclear fuel in its core in a hurry. So even though P Cygni is only a few million years old – compared to four and a half billion years for the Sun – it’s nearing its end.
The earlier outbursts might have erupted because the star’s interior is unstable. It gets so hot that the star blasts some of the gas at its surface into space. There’s evidence that similar outbursts took place thousands of years earlier.
P Cygni is likely to explode within a couple of million years. Its core might collapse to form a super-dense neutron star – or even a black hole.
Under dark skies, P Cygni is visible to the eye alone. At nightfall, it’s in the east-northeast, close to the right of Sadr, the bright star that connects the swan’s body to its wings.
More about the swan tomorrow.
Script by Damond Benningfield
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2:19
Cygnus Clusters
Cygnus, the swan, soars gracefully through summer nights. Its brightest star, Deneb, is in the northeast at nightfall. It marks the swan’s tail. The swan’s body stretches to the right, parallel to the horizon. The wings extend above and below, connected to the body by the star Sadr.
Cygnus contains many star clusters. The list includes several that stretch from Sadr to the south, roughly along the swan’s neck. The clusters contain a few dozen to a few hundred stars. All of them are young – no more than about 10 million years old. And many of them are especially hot, bright, and massive.
The clusters are indirectly related. They belong to much larger collections of young stars, plus the raw materials for making more stars. A “wave” passed through that region of the galaxy, squeezing gigantic clouds of gas and dust. Clumps of material within the clouds collapsed, forming stars.
Over the next few million years, the most massive stars will explode as supernovas. Shockwaves from the blasts may compress more pockets of gas and dust, creating more stars. But the clusters themselves won’t survive much longer – at least on the galactic timescale. They’ll be pulled apart by the gravity of the surrounding stars and clouds, so their stars will go their separate ways.
The clusters are easy targets for good binoculars. One is just a whisker from Sadr. Several others trail off to the right – sparkly decorations for the swan.
Script by Damond Benningfield
New Zealand