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Arecibo Observatory's Greatest Triumphs – Gizmodo

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The Arecibo Observatory in Puerto Rico.
Image: NAIC

Yesterday brought the tragic news that the famous 1,000-foot radio dish at the Arecibo Observatory in Puerto Rico will have to be demolished after the failure of two support cables. It’s the end of an era, but a good excuse to revisit some of the most important scientific contributions made possible by the famous facility.

Strategically built inside a sinkhole, the Arecibo Observatory has been at the center of all sorts of scientific breakthroughs for the past 57 years. The radio dish has made invaluable contributions to planetary and stellar science, the study of small-bodied objects like asteroids, cosmology, and even the search for extraterrestrial intelligence.

Here are some key highlights from Arecibo’s illustrious career. RIP.

NASA’s Mariner 10 spacecraft captured this photo of Mercury in 1974.

NASA’s Mariner 10 spacecraft captured this photo of Mercury in 1974.
Image: NASA/JLP

Arecibo’s first major discovery came in 1967, when data gathered by the radio telescope showed that a year on Mercury is 59 days long, not 88 days as previously assumed.

Visual demonstration of the message, with color added to distinguish the various sections.

Visual demonstration of the message, with color added to distinguish the various sections.
Illustration: Wikimedia

A cool thing about the Arecibo Observatory is that, in addition to receiving radio signals, it can also transmit them. This capability was put to the test in 1974 when the facility beamed a transmission, known as the Arecibo message, to globular star cluster M13. This region of space is approximately 25,000 light-years away, so we’ll have to be patient about receiving a response.

Written in binary, the message was short, depicting things like DNA, the human form, and even a digital representation of the Arecibo Observatory itself. In case you’re wondering, here’s what the transmission looks like:

00000010101010000000000001010000010100000001001000100010001001011001010101010101010100100100000000000000000000000000000000000001100000000000000000001101000000000000000000011010000000000000000001010100000000000000000011111000000000000000000000000000000001100001110001100001100010000000000000110010000110100011000110000110101111101111101111101111100000000000000000000000000100000000000000000100000000000000000000000000001000000000000000001111110000000000000111110000000000000000000000011000011000011100011000100000001000000000100001101000011000111001101011111011111011111011111000000000000000000000000001000000110000000001000000000001100000000000000010000011000000000011111100000110000001111100000000001100000000000001000000001000000001000001000000110000000100000001100001100000010000000000110001000011000000000000000110011000000000000011000100001100000000011000011000000100000001000000100000000100000100000001100000000100010000000011000000001000100000000010000000100000100000001000000010000000100000000000011000000000110000000011000000000100011101011000000000001000000010000000000000010000011111000000000000100001011101001011011000000100111001001111111011100001110000011011100000000010100000111011001000000101000001111110010000001010000011000000100000110110000000000000000000000000000000000011100000100000000000000111010100010101010101001110000000001010101000000000000000010100000000000000111110000000000000000111111111000000000000111000000011100000000011000000000001100000001101000000000101100000110011000000011001100001000101000001010001000010001001000100100010000000010001010001000000000000100001000010000000000001000000000100000000000000100101000000000001111001111101001111000

You can find a full explanation of the Arecibo message here.

Artist’s impression of a binary pulsar.

Artist’s impression of a binary pulsar.
Image: Jodrell Bank Observatory, University of Manchester/Wikimedia

Pulsars—rapidly spinning stars that shoot beams of electromagnetic radiation from their highly magnetic poles—were first discovered in 1967. Researchers using the Arecibo Observatory in 1974 did one better by discovering the first binary pulsar, in which a pulsar orbits another star. The discovery earned Joseph Taylor and Russell Hulse the 1993 Nobel Prize in Physics.

Radar map of Venus.

Radar map of Venus.
Image: NAIC

In 1981, Arecibo provided the first radar maps of Venus—a planet perpetually covered in clouds. The dish would provide even more detail of Venus in the following years.

Asteroid 2001 GQ2, as imaged by the Arecibo in April 2001.

Asteroid 2001 GQ2, as imaged by the Arecibo in April 2001.
Image: NAIC

Arecibo spotted its first asteroid in 1989, an object named 4769 Castalia. The observatory would go on to find many more and collect important data about potentially dangerous near-Earth objects. One of the more regrettable aspects of the dish having to be shut down is that Arecibo will no longer scour the skies in search of potential threats.

Arecibo radar image showing ice at Mercury’s north pole.

Arecibo radar image showing ice at Mercury’s north pole.
Image: NAIC

The closest planet to the Sun, Mercury, has ice at both its north and south poles, which we learned in 1992 thanks to observations made by Arecibo. The deposits are presumably water ice, evidence of volatile materials on Mercury’s surface. This ice “persists in shadowed craters despite the high temperatures, 800°F, at the surface,” according to the National Astronomy and Ionosphere Center, which is the formal name of the Arecibo Observatory.

Artist’s impression of the first exoplanet ever discovered, which happens to orbit a pulsar.

Artist’s impression of the first exoplanet ever discovered, which happens to orbit a pulsar.
Illustration: NASA/JPL-Caltech

In 1992, astronomer Aleksander Wolszczan used the Arecibo telescope to spot three exoplanets around a pulsar named PSR B1257+12. These were the first planets ever discovered outside of our solar system, and a big step forward in our understanding of the cosmos.

Artist’s impression of gravitational waves generated by binary neutron stars.

Artist’s impression of gravitational waves generated by binary neutron stars.
Image: R. Hurt/Caltech-JPL

Gravitational waves—ripples in the fabric of spacetime caused by tremendous events like colliding black holes or supernovae—were finally confirmed by scientists in 2016, after being predicted by Albert Einstein a century ago. This monumental discovery, made by the Laser Interferometer Gravitational-wave Observatory (LIGO), might not have been possible had it not been for Arecibo, as NAIC explains:

Indeed, the first evidence for the existence of gravitational waves came from long-term Arecibo observations of a pulsar in a decaying orbit with another neutron star, where the rate of orbital shrinkage matched the rate expected from the loss of energy carried away by emitted gravitational waves.

Artist’s impression of a powerful X-ray burst erupting from a magnetar—a known source of fast radio bursts.

Artist’s impression of a powerful X-ray burst erupting from a magnetar—a known source of fast radio bursts.
Image: NASA’s Goddard Space Flight Center/Chris Smith (USRA

Scientists first detected fast radio bursts (FRBs) in 2007, but two major factors prevented them from fully understanding these enigmatic, millisecond-long pulses. The first is that all of them (until recently) originated in galaxies far, far away. The second is that FRBs were fleeting, one-off events. That changed in 2016, when scientists working at the Arecibo Observatory spotted the first repeating FRB. Since that time, we have detected other repeaters and even FRBs originating from our own galaxy. Recent evidence suggests these pulses are coming from highly magnetic neutron stars known as magnetars.

Artist’s impression of a pulsar.

Artist’s impression of a pulsar.
Illustration: NASA

In one of the more unexpected astronomical discoveries, scientists used the facility to detect two rather odd pulsars that stopped blinking for intermittent periods. The discovery, made in 2017, suggests pulsars don’t always blink, and that they have an “on state” and an “off state.” What’s more, this research suggests there may be more intermittent pulsars than “normal” pulsars.

A view of the Milky Way.

A view of the Milky Way.
Image: NASA

Despite these incredible discoveries, Arecibo is probably most famous for its use in SETI—the search for extraterrestrial intelligence. The observatory has been used by such groups as SETI@Home, the SETI team at the University of California, Berkeley, and the SETI Institute’s Project Phoenix. The dish was even featured in the 1997 film Contact. No radio signals from aliens have ever detected by Arecibo (nor by any other observatory, for that matter), which is, in and of itself, an interesting observation—one that’s forcing us to ask: Where is everybody?

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Beaver moon eclipsed by Earth's shadow tonight | Georgia Straight Vancouver's News & Entertainment Weekly – Straight.com

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November’s full moon will undergo a partial eclipse after midnight Sunday (November 29) when it slides across the outer (penumbral) edge of Earth’s shadow during the early hours of November 30.

This moon—sometimes called the beaver moon because it comes at a time when beavers are stepping up activities to prepare for the cold winter months ahead—will rise in the east and climb the night sky until the start of the eclipse.

Because the full moon will not cross into the darkest part of our planet’s shadow (the umbra), the eclipse—which will affect about 83 percent of the satellite’s surface—will be seen as a darkening of the affected area.

The partial eclipse will start at 1:42 a.m., when the moon should be high overhead and to the southwest. The moon will take more than four hours to traverse the Earth’s penumbra.

When the moon sets, at 6:56 a.m. Vancouver time, it should be coloured orange.

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NOAA scientists discover new species of gelatinous animal near Puerto Rico – CTV News

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Scientists have discovered a new species of ctenophore, or comb jelly, near Puerto Rico.

The newly named Duobrachium sparksae was discovered two and a half miles below sea level by the National Oceanic and Atmospheric Administration Fisheries research team. It was found during an underwater expedition using a remotely operated vehicle in 2015 and filmed by a high-definition camera.

NOAA Fisheries scientists Mike Ford and Allen Collins spotted the ctenophore and recognized it as a new species. This is the first time NOAA scientists have identified a new species using only high-definition video, according to NOAA.

“The cameras on the Deep Discoverer robot are able to get high-resolution images and measure structures less than a millimeter. We don’t have the same microscopes as we would in a lab, but the video can give us enough information to understand the morphology in detail, such as the location of their reproductive parts and other aspects,” Collins said.

The scientists also said there was another unique quality to the discovery. During the expedition, they were not able to gather any samples, so the video evidence is all they have.

“Naming of organisms is guided by international code, but some changes have allowed descriptions of new species based on video — certainly when species are rare and when collection is impossible,” Ford said. “When we made these observations, we were 4,000 metres down, using a remote vehicle, and we did not have the capabilities to take a sample.”

There are between 100 and 150 species of comb jellies, and despite their name, they are not related to jellyfish at all, according to the NOAA. The species is carnivorous, and many are highly efficient predators that eat small arthropods and many kinds of larvae.

The researchers said that there did not initially get a long look at the animal, so there is still a lot about this new species that they do not know yet. Their findings were recently published in the journal Plankton and Benthos Research.

“We’re not sure of their role in the ecosystem yet,” Ford said.

“We can consider that it serves similar roles to other ctenophores near the ocean floor and it also has some similarities to other ctenophores in open ocean areas,” he said.

The videos are now part of the Smithsonian National Museum of Natural History Collection and publicly accessible.

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You might want to stay up late: lunar eclipse to coincide with November’s Beaver full moon early Monday morning – Toronto Star

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A special celestial event is set to grace Toronto skies early Monday morning.

The November full moon, which is traditionally called the Beaver moon, will coincide with a penumbral lunar eclipse.

This kind of eclipse event happens when the moon crosses Earth’s outer shadow, or penumbra, giving it a reddish brown hue.

Those in Toronto will be able to observe the phenomenon starting 2:29 a.m. ET. The eclipse will be at its peak at 4:42 a.m. ET.

Environment Canada predicts partly cloudy skies at that time, but stargazing enthusiasts may be able to get a glimpse of the moon.

Although the Canadian Space Agency notes lunar eclipses are usually among the most observable because you can see them — quite safely — with the naked eye, with the more subtle penumbral eclipse they recommend using binoculars or a small telescope for the best viewing experience.

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