Blog
Unveiling the clouds of Venus
Tuesday, December 28th 2021 07:40 PM
The dense clouds of Venus are on full display in this ultraviolet image taken by the Pioneer Venus Orbiter on Feb. 5, 1979. Venus’ clouds have long been known to absorb ultraviolet radiation, but exactly how and why remains a mystery.
As brilliant and splendid as Venus is to the naked eye, the world often ranks as one of astronomy’s great telescopic disappointments. Apart from its evolving phase and its dazzling, ubiquitous cloud deck, the casual observer can see very little detail. As brilliant and splendid as Venus is to the naked eye, the world often ranks as one of astronomy’s great telescopic disappointments. Apart from its evolving phase and its dazzling, ubiquitous cloud deck, the casual observer can see very little detail.
The famed English amateur astronomer William F. Denning wrote in Telescopic Work for Starlight Evenings (1891): “When the telescope is directed to Venus it must be admitted that the result hardly justifies the anticipation. O...
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Discover the sky’s best double stars
Thursday, December 23rd 2021 06:05 PM
The Big Dipper in Ursa Major houses a famous double star that ancient Arabic texts refer to as a visual test. Just at the kink in the Dipper’s handle is bright Mizar, with dimmer Alcor 12' to its east-northeast (upper left in this image).
Viewing double stars is a popular activity at star parties. The presenter will usually point out Mizar and its dimmer companion, Alcor, in the bend of the Big Dipper’s handle; or, in summer, telescopes are often turned to Albireo in Cygnus, to everyone’s delight.
But double stars are often neglected by today’s serious amateur observers, who are more interested in deep-sky objects. It’s a shame, because not only are double stars beautiful, but they are also a challenge by which to measure the skill of the observer and the quality of their telescope. Double stars were once the focus of both professional and amateur observers alike, and they have played an important role in our understanding of gravity and of the g...
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Snapshot: Milky Way stars photobomb distant galaxy
Tuesday, December 21st 2021 05:37 PM
Located some 230 million light-years away in the constellation Aquila the Eagle is the majestic galaxy UGC 11537. Because this distant, tightly wound spiral appears so near the plane of our own Milky Way, two foreground stars are prominently photobombing UGC 11537 in this Hubble Space Telescope image. Each of these foreground stars displays a strong starburst effect, which is an optical artifact that results from starlight hitting Hubble’s secondary mirror, producing so-called diffraction spikes.
Three examples of image artifacts appearing in NASA images. LEFT: Venus appears like a butterfly of light in this STEREO coronagraph image due to the way the instrument bent its incoming light. MIDDLE: Venus is again affected by an artifact, this time appearing to streak to the sides caused by an excess signal. RIGHT: NASA's STEREO coronagraph caught this image of a highly energetic particle passing through the instrument.
But starbursts aren’t the only example o...
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Image of the Day: Blueprints of the James Webb Space Telescope
Monday, December 20th 2021 05:27 PM
These blueprints of the James Webb Space Telescope were created as a prop for a video series, but since it was requested, we are offering them as a download! (Look close and you'll notice some of the smaller text is Latin!)
Webb is targeted to launch at 7:20 a.m. EST Friday, Dec. 24, on an Arianespace Ariane 5 rocket from Europe’s Spaceport in Kourou, French Guiana, on the northeastern coast of South America.
Image Credit: NASA
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The Sky This Week: Winter officially begins
Friday, December 17th 2021 05:26 PM
Northern lights: Jupiter and Venus set amid the northern lights as seen from Ruka, Finland, in early 2012.
Friday, December 17
2021’s best comet, C/2021 A1 (Leonard), floats just 5° below Venus in the evening sky tonight. Depending on the Leonard’s current magnitude, it may be just visible to the naked eye in the falling twilight.
To catch the stunning scene, turn southwest after sunset. You absolutely won’t be able to miss Venus’ magnitude –4.9 glow, still 20° above the horizon as the Sun disappears. Let the sky begin to darken and your eyes adjust with it as you start scanning for Leonard’s faint, fuzzy coma.
Binoculars will greatly aid your search, but make sure the Sun is completely gone from the sky before pulling them out. If you’re an astrophotographer, you won’t want to miss this picturesque view, and photographs will certainly bring out Leonard’s still-bright dust tail and enhance the amount of i...
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NASA’s ‘Eyes on Asteroids’ Reveals Our Near-Earth Object Neighborhood
Monday, December 13th 2021 05:19 PM
With NASA’s Eyes on Asteroids, you can watch all the known near-Earth asteroids and comets as they orbit the Sun. Updated twice daily with the latest tracking data, the web-based application will automatically add new near-Earth object discoveries for you to explore.
Learn more about the growing population of near-Earth objects with NASA’s new 3D real-time web-based application.
Through a new 3D real-time visualization tool, you can now explore the asteroids and comets that approach Earth’s orbital neighborhood – and the spacecraft that visit these objects – with a click or a swipe. NASA’s Eyes on Asteroids brings this data to any smartphone, tablet, or computer with an internet connection – no download required.
Thousands of asteroids and dozens of comets are discovered every single year, some of which – called near-Earth objects (NEOs) – follow orbits that pass through the inner solar system. Now totaling about 28,000, their...
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The Sky This Week: Catch Comet Leonard at its best
Friday, December 10th 2021 05:16 PM
Leonard’s time to shine: Comet C/2021 A1 (Leonard) is on fine display this week after passing by the globular cluster M3 early in the month.
Friday, December 10
The Moon passes 0.5° north of asteroid 2 Pallas in Aquarius at 8 A.M. EST; meanwhile, asteroid 44 Nysa reaches opposition in Taurus the Bull at 9 A.M. EST. Although these objects are below the horizon and the sky is light, if you wait until this evening, you can spot these asteroids in the nighttime sky.
Pallas is the third-largest asteroid in the main belt. By two hours after sunset, the Moon has pulled away slightly and sits 6.2° east-northeast of the 10th-magnitude asteroid. For a closer signpost, start at 3rd-magnitude Skat (Delta [δ] Aquarii). Pallas sits 3.7° north-northeast of this star tonight.
Nysa is about a magnitude brighter than Pallas. You’ll want to give it until about 7:30 P.M. local time to get high enough for good viewing in Taurus, located above Orion in the s...
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Capture the cosmos with your smartphone
Wednesday, December 8th 2021 05:17 PM
These days, even your smartphone’s camera can capture some amazing shots of the cosmos, as proven by this view of the Orion Nebula (M42) taken through a 12-inch telescope.
When I was 6 years old, my older brother helped me kick off my journey to becoming an amateur astronomer by taking me out to our backyard in southern Indiana and giving me tours of the night sky. Besides showing me the Moon, planets, and stars, he pointed out that the constellation Cassiopeia formed my initials: M and W. His passion for the cosmos is what first sparked my interest in astronomy and science in general.
Later, when I was a teenager in 1961, I received my first telescope as a Christmas present from my mother: an Edmund Scientific 3-inch f/10 Newtonian reflector. The following year, I started taking photographs through that telescope using her roll-film box camera — remember those? Over the next several years, I continued taking occasional astrophotos through the modest scope using a...
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Image of the Day: Eclipse Over Antarctica
Monday, December 6th 2021 07:29 PM
Image of the Day: Eclipse Over Antarctica
This image of our home planet shows how Earth looked from more than 950,000 miles, or 1.5 million kilometers, away during the total solar eclipse visible in Antarctica on Dec. 4, 2021. The EPIC instrument on the DSCOVR spacecraft captured the eclipse's umbra, the dark, inner shadow of planet Earth. Shaped like a cone extending into space, it has a circular cross section most easily seen during an eclipse.
Image Credit: NASA
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The Sky This Week: The Moon gets busy
Friday, December 3rd 2021 05:45 PM
Total solar eclipse: This stunning image of the July 11, 2010, total solar eclipse was taken from Easter Island. December 4’s total solar eclipse will touch only the continent of Antarctica.
Friday, December 3
With no Moon in the sky tonight, it’s time to enjoy a classic target at its best: the Orion Nebula (M42). Hanging below Orion’s Belt about 3.7° south-southwest of magnitude 1.7 Alnitak, M42 covers a broad swatch of sky spanning 85' by 60'. Its 4th-magnitude glow is easily visible to the naked eye under good conditions, but turn binoculars or a telescope on this magnificent star-forming factory and you’re in for a real treat.
Because it is so large and bright, M42 offers a wealth of detail so conspicuous that several features have well-known nicknames. The Fish’s Mouth refers to the dark dust lane at M42’s northern edge, which separates it from the smaller M43. The bright region at the nebula’s western side is called...
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