Earth/Sky: A novel approach to star trails

A novel approach to star trails

Earth/Sky for tonight

see I was nearly correct in what I viewed in the Night Sky last night. But let’s let them explain it to you.

Moon, Jupiter, Spica on June 4

Earth/Sky News

Hidden galaxies, Mars lakes, uncertain asteroid

Deborah Byrd explains the science behind recent headlines:

EarthSky Pluto

EarthSky // Science Wire, Space     Release Date: Feb 08, 2016

The hills are thought to be fragments of Pluto’s rugged uplands that have broken away and are being carried along the flow paths of glaciers.

 

Hills of water ice on Pluto ‘float’ in a sea of frozen nitrogen. They’re thought to move slowly over time, somewhat like icebergs in Earth’s Arctic Ocean. For the scale here, notice the feature informally named Challenger Colles – honoring the crew of the lost Space Shuttle Challenger. It appears to be an especially large accumulation of these hills, measuring 37 by 22 miles (60 by 35 km). Image via NASA/JHUAPL/SwRI

Just when you think Pluto couldn’t get any more fascinating, it does. NASA said on February 4, 2016 that numerous, isolated hills – possibly fragments of water ice from Pluto’s surrounding uplands – are floating on the nitrogen ice glaciers on the little world’s surface. This is happening in the beautiful heart-shaped feature on Pluto known as Sputnik Planum. NASA said the hills individually measure one to several miles or kilometers across. The images suggesting them come, of course, from NASA’s New Horizons spacecraft, which streaked past Pluto last July and is still sending its data back to Earth. In a statement, NASA said the hills are:

    … likely miniature versions of the larger, jumbled mountains on Sputnik Planum’s western border. They are yet another example of Pluto’s fascinating and abundant geological activity.

    Because water ice is less dense than nitrogen-dominated ice, scientists believe these water ice hills are floating in a sea of frozen nitrogen and move over time like icebergs in Earth’s Arctic Ocean.

    The hills are likely fragments of the rugged uplands that have broken away and are being carried by the nitrogen glaciers into Sputnik Planum. ‘Chains’ of the drifting hills are formed along the flow paths of the glaciers.

    When the hills enter the cellular terrain of central Sputnik Planum, they become subject to the convective motions of the nitrogen ice, and are pushed to the edges of the cells, where the hills cluster in groups …

New Horizons obtained the inset image above – showing the hills – at a range of approximately 9,950 miles (16,000 km) from Pluto, about 12 minutes before New Horizons’ closest approach to Pluto on July 14, 2015.

Thank you very much, Skeen! I appreciate these articles! You’re awesome!! 😀

Full moon on January 23-24, 2016

Tonight: January 23, 2016

This full moon falls on January 24 at 1:46 Universal Time. Although the moon turns full at the same instant worldwide, the clock time – and possibly the date – differ by time zone. For the mainland United States, the moon reaches the crest of its full phase on this Saturday evening on January 23 at 8:46 p.m. EST, 7:46 p.m. CST, 6:46 p.m. MST or5:46 p.m. PST.

The January 2016 full moon counts as the second full moon after the December solstice. In North America, we often call this full moon the Wolf Moon, Snow Moon or Hunger Moon.

Astronomically speaking, the moon is full at the moment that it’s most opposite the sun in its orbit (180o from the sun in celestial or ecliptic longitude). For general reference, however, we can say the moon is full all night tonight, lighting up the nighttime from dusk until dawn.

Elsewhere around the world, the moon reaches the crest of its full phase at different times on the clock. Looking at the worldwide map below, you can see that the full moon comes at midnight for the Atlantic Ocean, noon for the Pacific Ocean, sunset (January 23) in Alaska and sunrise (January 24) in Asia. All these places will see a full-looking moon lighting up the sky tonight from dusk until dawn.

But to see the moon at the instant of a full moon, the moon has to be above your horizon on the nighttime side of the world.

In both the Northern and Southern Hemispheres, the January sun – unlike the January full moon – rises south of due east and sets south of due west. In the Northern Hemisphere, these far-southern risings and settings of the sun give us the short days of winter. South of the equator, the same far-southern sunrises and sunsets bring long summer days. Meanwhile, the full moon lies opposite the sun, mirroring the sun’s place in front of the backdrop stars for six months hence.

And that’s why tonight’s moon – like the sun in summer – will follow a high path across the sky as seen from the northern part of the globe – and a low path as seen from the southern.

This January full moon rises north of due east around sunset, climbs highest in the sky around midnight and sets north of due west around sunrise.

Can you tell me the full moon names?

EarthSky // Astronomy Essentials, Science Wire    

Release Date: Jan 23, 2016

For both the Northern and Southern Hemispheres, the full moons have names corresponding to the calendar months or the seasons of the year

Some almanacs like to give each month a special full moon name. Other almanacs like to reference full moons relative to seasonal markers, as defined by equinoxes and solstices. Is one way better than the other? No. Both have their roots in folklore. Of course, both the monthly names and the seasonal names necessarily favor either the Northern or Southern Hemisphere. That’s because the moon has different characteristics in the two hemispheres, at opposite times of the year. For example, the Harvest Moon is the full moon closest to the autumnal equinox. So it falls in September or October for the Northern Hemisphere, and it falls in March or April for the Southern Hemisphere.

Full moon setting. Photo credit-Carl Galloway

Northern Hemisphere full moon names by month:

January: Old Moon, Moon After Yule

February: Snow Moon, Hunger Moon, Wolf Moon

March: Sap Moon, Crow Moon, Lenten Moon

April: Grass Moon, Egg Moon

May: Planting Moon, Milk Moon

June: Rose Moon, Flower Moon, Strawberry Moon

July: Thunder Moon, Hay Moon

August: Green Corn Moon, Grain Moon

September: Fruit Moon, Harvest Moon

October: Harvest Moon, Hunter’s Moon

November: Hunter’s Moon, Frosty Moon, or Beaver Moon

December: Moon Before Yule, or Long Night Moon

Southern Hemisphere full moon names by month:

January: Hay Moon, Buck Moon, Thunder Moon, Mead Moon

February (mid-summer): Grain Moon, Sturgeon Moon, Red Moon, Wyrt Moon, Corn Moon, Dog Moon, Barley Moon

March: Harvest Moon, Corn Moon

April: Harvest Moon, Hunter’s Moon, Blood Moon

May: Hunter’s Moon, Beaver Moon, Frost Moon

June: Oak Moon, Cold Moon, Long Night’s Moon

July: Wolf Moon, Old Moon, Ice Moon

August: Snow Moon, Storm Moon, Hunger Moon, Wolf Moon

September: Worm Moon, Lenten Moon, Crow Moon, Sugar Moon, Chaste Moon, Sap Moon

October: Egg Moon, Fish Moon, Seed Moon, Pink Moon, Waking Moon

November: Corn Moon, Milk Moon, Flower Moon, Hare Moon

December: Strawberry Moon, Honey Moon, Rose Moon

***About once every 19 years, February has no full moon at all.***

Moreover, in 7 out of every 19 years, two full moons will fall in the same calendar month. The second of the month’s two full moons is popularly referred to as a Blue Moon.

Full moon names by season (Northern or Southern Hemisphere):

After the winter solstice:

Old Moon, or Moon After Yule

Snow Moon, Hunger Moon, or Wolf Moon

Sap Moon, Crow Moon or Lenten Moon

After the spring equinox:

Grass Moon, or Egg Moon

Planting Moon, or Milk Moon

Rose Moon, Flower Moon, or Strawberry Moon

After the summer solstice:

Thunder Moon, or Hay Moon

Green Corn Moon, or Grain Moon

Fruit Moon, or Harvest Moon

After the autumnal equinox:

Harvest Moon, or Hunter’s Moon

Hunter’s Moon, Frosty Moon, or Beaver Moon

Moon Before Yule, or Long Night Moon

There are usually three full moons in between an equinox and a solstice, or vice versa. Seven times in 19 years, four full moons fall in a single season. In that case, the third of a season’s four full moons is also called a Blue Moon. The next Blue Moon by this definition will happen on May 21, 2016.

Thank you, Skeen! You’re Awesome! ❤

Galactoseismology

Published on 14 Jan 2016
Deborah delivers the headlines of the past few days. First up, a new word for you … “galactoseismology,” the study of galaxy-wide quakes in our Milky Way. At the end … a stirring new video on the dramatic upright landing of SpaceX’s Falcon 9 rocket, in December. This Sunday, SpaceX will try again for an upright rocket

 https://www.youtube.com/watch?v=GsAWg_9_uYg#t=52

Earthrise photo

A new earthrise photo, as seen from the moon by the Lunar Reconnaissance Orbiter

Spectacular new image of earthrise seen from the moon, from NASA’s Lunar Reconnaissance Orbiter using cameras operated by Arizona State University. Africa, the south Atlantic Ocean and the eastern edge of South America can be seen. The large tan area on the upper right is the Sahara Desert. In the foreground on the moon, you are seeing the Compton crater.

As seen from any one spot on the moon’s surface, Earth never rises or sets. Because one side of the moon always faces Earth, the Earth hangs relatively motionless in the lunar sky. But orbiting spacecraft can see earthrises and earthsets. This week, Arizona State University emailed this amazing new image of an earthrise seen from the moon, along with Q-and-A with Mark Robinson, who is the principal investigator for the cameras aboard NASA’s Lunar Reconnaissance Orbiter. In it, Robinson talked about this image, which was acquired by the orbiter’s camera (the LROC) in October.

    Q: How did you know this image would be possible?

    A: [The LROC has] taken pictures of the Earth more than 10 times in the past. We wanted to get a limb shot (showing the edge of the moon). What makes it really hard is getting the moon in the foreground … That was not by accident. We have software tools that allow us to visualize observations. We know where the spacecraft is going to be in the future … We determined from which orbits the Earth will be visible near the limb. Once we know the ground track where the Earth will be visible, we then find a view with a dramatic foreground.

    Question: What are some of the pieces that had to come together to make this photo?

    Answer: Just a few of the steps: You have to roll the spacecraft, in this case about 70 degrees, but the spacecraft is traveling at over 1,600 meters per second. We’re restricted in the length of one exposure time to something close to 0.4 milliseconds. You also move the spacecraft in the direction of flight so that you can get a wide enough field of view. When a spacecraft is in an elliptical orbit, the timing changes from image-to-image in an orbit. We have to compute all of that beforehand to get it exactly right … That timing has to be precisely carried out … We have to predict the temperature of the CCD (electronic equivalent of film). The Wide Angle Camera (WAC) is imaging an area multiple times while the Narrow Angle Cameras (NAC) takes just one picture. We blow up the WAC images and combine them to produce higher resolution, and then overlay this sharper image on the NAC image. We wanted the Earth to be on the horizon, and that only happens from certain areas of the moon. It’s only when the spacec    raft is above the boundary between the nearside and farside that you can see the Earth behind the limb (edge of the moon).

    Q: LRO has been in orbit for more than six years. If you picked the best shots to show your friends, what are they?

    A: We’ve taken more than a million images. My answer changes every three days. The Apollo landing sites are fantastic. You can see the tracks the astronauts left on the surface of the moon. To me, as a scientist, it’s really great because it helps me visualize the photographs they took on the surface. The significance of the geologic context. ‘All right, now I know they got that soil sample there, and I can see what it looks like.’

Thank you, Skeen for the article! xoxo 

Start 2016 with a sky challenge.

Start 2016 with a sky challenge. The Quadrantid meteor shower peaks in moon-free skies, between midnight and dawn on January 4.

The annual Quadrantid shower is nominally active during the first week of January, and is best seen from northerly latitudes. However, peak activity lasts less than a day. So you need to be on the night side of Earth when this shower exhibits its relatively short peak to witness the Quadrantids. In 2016, we don’t expect the waning crescent moon to seriously obtrude on this meteor shower. So if you’re game, try watching between midnight and dawn on January 4.

This meteor shower favors the Northern Hemisphere. That’s because its radiant point – the point in the sky from which the meteors appear to radiate – is far to the north on the sky’s dome.

The Quadrantid meteor shower is capable of matching the meteor rates of the better known August Perseid and December Geminid showers. It has been known to produce up to 50-100 or more meteors per hour in a dark sky.

So why isn’t the Quadrantid shower as celebrated as the Perseid and Geminid showers? It’s because the Quadrantid shower has a narrow peak that lasts for only a few hours. If you miss the peak – which is easy to do – you won’t see many meteors.

If you’re thinking of watching the Quadrantids, do it. Meteor shower peaks are rarely certain, and sometimes a gamble on a shower will reward you with a good show. Just be aware you might not see a whole lot of meteors! No matter where you are in the Northern Hemisphere, the best time to watch is between midnight and dawn, local time. Fortunately, the waning crescent moon shouldn’t intrude too greatly on the January 2016 Quadrantid meteor shower!

The Quadrantid shower is named after the defunct 19th-century constellation Quadrans Muralis. If you trace the paths of the Quadrantids backward, they appear to radiate from a point where this constellation once reigned in the sky. If you wish, you can locate the Quadrantid radiant in reference to the Big Dipper and the bright star Arcturus. Use the chart at the top of this post.

But you don’t need to find the radiant to enjoy the Quadrantids. You need a dark, open sky, and you need to look in a general north-northeast direction for an hour or so before dawn. That’s the Quadrantid meteor shower – from late night January 3 to dawn January 4, 2016 – for the world’s northerly latitudes. Who knows? This shower can produce up to 50 or more meteors per hour, but its peak is rather short and sweet. Just before dawn on January 4, the waning crescent moon will be rather close to Mars, and you can use the moon and Mars to guide you to three more morning planets. Jupiter shines to the west of the moon and Jupiter, and the planets Venus and Saturn sit low in the southeast during the dark hour before dawn.

It’ll be worth getting up in the wee hours just to see the lineup of planets. The green line depicts the ecliptic – Earth’s orbital plane projected onto the dome of sky.

Hidden Lair at the Heart of Galaxy NGC 1068

Galaxy NGC 1068 can be seen in close-up in this view from NASA’s Hubble Space Telescope. NuSTAR’s high-energy X-rays eyes were able to obtain the best view yet into the hidden lair of the galaxy’s central, supermassive black hole. This active black hole — shown as an illustration in the zoomed-in inset — is one of the most obscured known, meaning that it is surrounded by extremely thick clouds of gas and dust.

In the view of modern astronomers, a supermassive black hole at the center of a distant galaxy is likely encircled by thick, doughnut-shaped disk or torus of gas and dust. The material in these tori is what feeds an active black hole, that is, one that’s still growing.

Telescopes couldn’t penetrate a supermassive black hole’s torus until recently, but now some can, and NASA released the amazing image above this month (December 17, 2015). It’s a peek inside one of the densest known of these tori, surrounding the black hole at the center of a well-studied spiral galaxy called NGC 1068 (aka M77), located some 47 million light-years away in the direction to the constellation Cetus the Whale. The telescope that acquired this image is called NuSTAR (NASA’s Nuclear Spectroscopic Telescope Array), and it used its X-ray vision to look inside the disk.

It has confirmed that the material in the disk isn’t smooth, but rather clumpy.

A NASA statement explained:

    Doughnut-shaped disks of gas and dust around supermassive black holes were first proposed in the mid-1980s to explain why some black holes are hidden behind gas and dust while others are not. The idea is that the orientation of the doughnut relative to Earth affects the way we perceive a black hole and its intense radiation. If the doughnut is viewed edge-on, the black hole is blocked. If the doughnut is viewed face-on, the black hole and its surrounding, blazing materials can be detected. This idea is referred to as the ‘unified model’ because it neatly joins together the different black hole types, based solely upon orientation.

    In the past decade, astronomers have been finding hints that these doughnuts aren’t as smoothly shaped as once thought. They are more like defective, lumpy doughnuts that a doughnut shop might throw away.

    The new discovery is the first time this clumpiness has been observed in an ultra-thick doughnut and supports the idea that this phenomenon may be common. The research is important for understanding the growth and evolution of massive black holes and their host galaxies.

wow, thank you, Skeen!