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The Sky This Week: Observe the Moon

Friday, October 15th 2021 09:31 AM

Setting satellite: The bright Moon sets in this photo taken October 1, 2012.   Friday, October 15 The Moon passes 4° south of Jupiter in Capricornus at 6 A.M. EDT. You can’t see them then — both are below the horizon — but they are visible in the sky tonight after sunset. By then, the Moon has shifted over into Aquarius and sits 8.2° east-southeast of Jupiter. The bright star Deneb Algedi (magnitude 2.9) sits between them, about one-third of the way on a line drawn from Jupiter (magnitude –2.6) to the Moon. Look to the right (west) of Jupiter and you’ll find Saturn, glowing softly at magnitude 0.5 on the other side of Capricornus. It sits 6° southeast of Beta (β) Capricorni. The ringed planet looks stunning through a telescope, with its trademark rings stretching 40" and several small moons around it, including Enceladus, Rhea, Dione, and Tethys. Brighter Titan sits just over 2' away, currently west-southwest of the planet. Sun...

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Image of the Day

Wednesday, October 13th 2021 09:19 AM

NASA's Lucy mission will explore a record-breaking number of asteroids, flying by one asteroid in the solar system’s main asteroid belt, and by seven Trojan asteroids. This illustration is of the Lucy mission's seven targets: the binary asteroid Patroclus/Menoetius, Eurybates, Orus, Leucus, Polymele, and the main belt asteroid DonaldJohanson. Lucy is scheduled to launch on Saturday, Oct. 16, 2021, at 5:34 a.m. EDT.   Image Credit: NASA/Goddard Space Flight Center Conceptual Image Lab

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The Sky This Week: All eyes on Uranus

Monday, October 11th 2021 09:46 AM

  A distant giant: The Hubble Space Telescope captured this colorful image of the ice giant Uranus in November 2016.   Friday, October 8 Today, tomorrow, and Sunday, the Royal Astronomical Society (RAS) is hosting a public livestream of the planet Uranus, as observed with NASA’s Infrared Telescope Facility on Mauna Kea in Hawaii. The livestream will run each morning from 4 A.M. through 11:55 A.M. EDT on the RAS YouTube Channel. But these observations are more than just a chance to enjoy clear views of the ice giant — they will also be used to create the most detailed infrared map of the planet to date. Researchers hope to catch the planet’s southern aurora to chart and learn more about it. If you want to find Uranus for yourself, it rises around 7:30 P.M. local time and will be well poised for observation in the east a few hours later. It’s approaching opposition, which it will reach next month. You’ll find it in the constellation Aries, whe...

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The Sky This Week: New Moon means dark skies

Friday, October 1st 2021 09:32 AM

  Venus and Scorpius: This picture, taken near Roque de Los Muchahos in La Palma, Spain, showcases brilliant Venus inside a stellar asterism that forms the constellation Libra the Scales. At left is the central region of the Milky Way and most of the constellation Scorpius, with its brightest star Antares at top center.   Friday, October 1 The 66-mile-wide (107 kilometers) asteroid 40 Harmonia reaches opposition this afternoon at 3 P.M. EDT. You can find it in Cetus the Whale tonight, visible all evening and into the early morning hours of the 2nd. An hour after sunset, look east, where magnitude 3.6 Iota (ι) Ceti is rising, already more than 6° high. Harmonia sits 7.7° east-northeast of this star. You can also use 5th-magnitude 20 Ceti as a jumping-off point: Harmonia is about 3.6° southwest of this luminary, roughly level with it in altitude as they rise. The longer you wait, the higher Harmonia will rise in the sky and the easier it will be to spot it...

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Understanding just how big solar flares can get

Wednesday, September 29th 2021 10:08 AM

  On May 1, 2019, the star next door erupted. In a matter of seconds, Proxima Centauri, the nearest star to our Sun, got thousands of times brighter than usual — up to 14,000 times brighter in the ultraviolet range of the spectrum. The radiation burst was strong enough to split any water molecules that might exist on the temperate, Earth-sized planet orbiting that star; repeated blasts of that magnitude might have stripped the planet of any atmosphere. It would be bad news if the Earth’s sun ever got so angry. But the Sun does have its moments — most famously, in the predawn hours of Sep. 2, 1859. At that time, a brilliant aurora lit up the planet, appearing as far south as Havana. Folks in Missouri could read by its light, while miners sleeping outdoors in the Rocky Mountains woke up and, thinking it was dawn, started making breakfast. “The whole of the northern hemisphere was as light as though the Sun had set an hour before,” the Times of Londo...

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What is the Harvest Moon effect?

Monday, September 27th 2021 09:44 AM

  A Full Harvest Moon hangs low in the sky above fields in Nebraska. For those in the Northern Hemisphere, the autumnal equinox marks the start of fall. This year, the equinox falls on Wednesday, September 22 at 3:21 P.M. EDT. At that time, the Sun will cross the celestial equator — the projection of Earth’s equator out into space in all directions — heading from north to south. The Full Moon that occurs closest to the autumnal equinox has a special name: the Harvest Moon. This year, the Harvest Moon falls just a few days before the equinox, on Monday, September 20, at 7:55 P.M. EDT. And because of some nifty celestial geometry, it brings with it a special effect called, appropriately, the Harvest Moon effect. What is the Harvest Moon effect? Put simply, it’s a span of several days during which the Full (or nearly Full) Moon rises at almost the same time each night. This means several nights in a row receive lots of bright moonlight — a boon to fa...

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Image of the Day

Friday, September 24th 2021 09:20 AM

On the night 175 years ago on Sept. 23-24, 1846, astronomers discovered Neptune, the eighth planet orbiting our Sun. The discovery was made based on mathematical calculations of its predicted position due to observed perturbations in the orbit of the planet Uranus. The discovery was made using a telescope since Neptune is too faint to be visible to the naked eye, and astronomers soon discovered a moon orbiting the planet. More than a century later, a second moon was discovered orbiting the planet. Our knowledge of distant Neptune greatly increased from the scientific observations made during Voyager 2’s flyby in 1989, including the discovery of five additional moons and confirmation of dark rings orbiting the planet. This image of Neptune was taken by Voyager 2 less than five days before the probe's closest approach of the planet on Aug. 25, 1989, and shows the "Great Dark Spot" — a storm in Neptune's atmosphere — and the bright, light-blue smudge of clouds that ac...

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Image of the Day

Wednesday, September 22nd 2021 09:27 AM

Time capsules from the birth of our Solar System more than 4 billion years ago, the swarms of Trojan asteroids associated with Jupiter are thought to be remnants of the primordial material that formed the outer planets. The Trojans orbit the Sun in two loose groups, with one group leading ahead of Jupiter in its path, the other trailing behind. Clustered around the two Lagrange points equidistant from the Sun and Jupiter, the Trojans are stabilized by the Sun and its largest planet in a gravitational balancing act. These primitive bodies hold vital clues to deciphering the history of the solar system, and perhaps even the origins of organic material on Earth. NASA's Lucy will be the first space mission to study the Trojans. The mission takes its name from the fossilized human ancestor (called “Lucy” by her discoverers) whose skeleton provided unique insight into humanity's evolution. Likewise, the Lucy mission will revolutionize our knowledge of pl...

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  This portion of the Hubble GOODS-South field contains hundreds of visible galaxies. A representative sample of those galaxies on the right half of the image also have their spectra overlayed in a representation of slitless spectroscopy. By using slitless spectroscopy, a spectrum is obtained that contains both spatial and wavelength information. For example, the inset highlights a spiral galaxy that shines brightly in the emission line of hydrogen-alpha (Ha) as well as in broad starlight (the horizontal strip of light). Its spiral shape is traced by the Ha portion of the spectrum. By combining imaging and spectroscopy, astronomers can learn much more than from each technique alone. Credit: NASA, ESA, and J. DePasquale (STScI) When NASA’s Nancy Grace Roman Space Telescope launches in the mid-2020s, it will revolutionize astronomy by providing a panoramic field of view at least 100 times greater than Hubble's at similar image sharpness, or resolution. The Roman Space Telesc...

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The Sky This Week: Keep an eye on the Moon

Monday, September 20th 2021 09:47 AM

  Messier 11: The Wild Duck Cluster, also cataloged as M11, is a bright open cluster that stays relatively visible even when the Moon is up.   Friday, September 17 The Wild Duck Cluster (M11) is a great target this evening. Located in Scutum, it’s still relatively high in the south after sunset. You can find M11 by dropping 1.8° southeast of 4th-magnitude Beta (β) Scuti, also known as 6 Aquilae. M11 is a bright, rich cluster of nearly 3,000 young stars estimated to be between 220 million and 250 million years old. With a visual magnitude of about 6, a keen-eyed observer might just be able to see it from a dark location — although the Moon may interfere with any attempts to find it without optical aid this evening. However, with either binoculars or a wide-field telescope, this beautiful cluster is easy to find and a real crowd-pleaser. It stretches about 14' across and its brightest stars form a rough v shape, which is how the cluster earned its name...

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