Dwarf planet Pluto news

This video says about itself:

22 March 2017

Researchers investigating Pluto think they have determined how the dwarf planet gets its red spots.

According to scientists with NASA‘s New Horizons mission, the hazy atmosphere is filled with particles that settle onto the surface.

In some areas, where the atmosphere has collapsed, the particles on the surface are exposed to more radiation from space that darkens them.

The researchers used data from a flyby mission in 2015.

Instruments onboard the New Horizons spacecraft found that the haze of particles reaches about 200 kilometers above the surface with 20 distinct layers.

From Science News:

How Pluto’s haze could explain its red spots

Collapse of atmosphere may influence blotchy surface colors

By Ashley Yeager

9:41am, March 22, 2017

Pluto may get its smattering of red spots from the fallout of its hazy blue skies, researchers say.

Haze particles from the dwarf planet’s atmosphere settle onto all of Pluto’s surface. But some regions may become redder and darker than others because parts of the atmosphere collapse, exposing those spots to more surface-darkening radiation from space, researchers report March 22 at the Lunar and Planetary Science Conference in The Woodlands, Texas.

“The atmospheric haze on Pluto was a spectacular surprise,” says NASA New Horizons mission scientist Andrew Cheng, a physicist at Johns Hopkins University. When the New Horizons spacecraft flew past Pluto in 2015, scientists weren’t expecting to see haze reaching at least 200 kilometers above the dwarf planet’s surface; nor were they expecting to see the haze divided into about 20 delicate and distinct layers (SN Online: 10/15/15).

These discoveries led researchers to suspect that the layers formed as a result of weak winds blowing across Pluto’s surface and over its mountains. Cheng and colleagues describe how the winds would shape the haze layers in a paper accepted in Icarus and posted online February 24 at arXiv.org. The team also explains how the atmosphere may affect the color of the dwarf planet’s surface features.

“Haze particles continually fall out onto the surface and rapidly build up,” Cheng says. This process should effectively “paint” the entire surface a uniform color — but Pluto isn’t a single color. It has strikingly bright and dark terrains, with some of the highest contrast found in the solar system. These dark and light regions form because portions of Pluto’s atmosphere periodically collapse, with air freezing and falling onto the dwarf planet’s surface, he and colleagues suggest.

When a section of the atmosphere collapses, parts of the surface are exposed directly to radiation from space, which would darken the surface particles there, Cheng explains. The richness of the reds, the team says, cannot be explained without some kind of collapse of the atmosphere, which does eventually redevelop.

Observations from NASA’s Kepler spacecraft also support the idea that Pluto’s atmosphere collapses. In fact, as Pluto moves away from the sun, most, if not all, of its atmosphere may collapse onto the dwarf planet’s surface, reported Carey Lisse, also of Johns Hopkins University, at the conference.

Exactly how much of Pluto’s atmosphere freezes out during its year, which lasts for 248 Earth years, isn’t clear. But that is currently being monitored, says Timothy Dowling, an atmospheric scientist at the University of Louisville in Kentucky, who was not involved in the new work. Pluto, he notes, won’t complete the first lap that humans have watched it make around the sun until 2178.

MAKE PLUTO A PLANET AGAIN A group of scientists have boarded the cause, as they know it’s pretty great. [HuffPost]

It’s time to redefine what qualifies as a planet, scientists propose. Redefinition would add Pluto back to the list, plus about 100 more. By
Ashley Yeager, 9:00am, March 23, 2017: here.

‘Saturn moon Mimas has no ocean’

This video says about itself:

23 October 2014

SciShow Space News takes you to the solar system’s own Death StarSaturn’s moon Mimas, where something mysterious is going on. Plus, we share a stunning new photo from the Hubble Space Telescope that holds a few surprises!

Hosted by: Caitlin Hofmeister.

From Science News:

Saturn’s ‘Death Star’ moon may not conceal an ocean after all

by Thomas Sumner

2:07pm, February 28, 2017

An ocean of liquid water probably doesn’t lurk beneath the icy surface of Mimas, Saturn’s smallest major moon, new calculations suggest. Scientists had proposed the ocean in 2014 to help explain an odd wobble in the moon’s orbit.

Other ocean-harboring moons, such as Jupiter’s Europa and Saturn’s Enceladus, are crisscrossed by fractures opened by strong tides that cause their oceans to bulge outward. Mimas, though freckled with craters, lacks any such cracks.

Planetary scientist Alyssa Rhoden of Arizona State University in Tempe and colleagues calculated whether Mimas’ icy shell could withstand the stress of a subsurface ocean pushing outward. Taking into account the moon’s elongated orbit, the researchers estimate that a subsurface ocean would produce tidal stresses larger than those on crack-riddled Europa. Mimas therefore probably doesn’t have an ocean, the researchers conclude February 24 in the Journal of Geophysical Research: Planets.

In new Cassini portraits, Saturn’s moon Pan looks like pasta, by Helen Thompson, 5:30pm, March 10, 2017: here.

Seven ‘earth-like’ planets discovered

This video says about itself:

NASA & TRAPPIST-1: A Treasure Trove of Planets Found

22 February 2017

Seven Earth-sized planets have been observed by NASA’s Spitzer Space Telescope around a tiny, nearby, ultra-cool dwarf star called TRAPPIST-1. Three of these planets are firmly in the habitable zone.

Over 21 days, NASA’s Spitzer Space Telescope measured the drop in light as each planet passed in front of the star. Spitzer was able to identify a total of seven rocky worlds, including three in the habitable zone, where liquid water might be found.

The video features interviews with Sean Carey, manager of the Spitzer Science Center, Caltech/IPAC; Nikole Lewis, James Webb Space Telescope project scientist, Space Telescope Science Institute; and Michaël Gillon, principal investigator, TRAPPIST, University of Liege, Belgium.

The system has been revealed through observations from NASA’s Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.

NASA’s Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.

From Phys.org:

Temperate earth-sized worlds found in extraordinarily rich planetary system

February 22, 2017

Astronomers have found a system of seven Earth-sized planets just 40 light-years away. They were detected as they passed in front of their parent star, the dwarf star TRAPPIST-1. Three of them lie in the habitable zone and could harbour water, increasing the possibility that the system could play host to life. It has both the largest number of Earth-sized planets yet found and the largest number of worlds that could support liquid water.

Astronomers using the TRAPPIST-South telescope at ESO’s La Silla Observatory, the Very Large Telescope (VLT) at Paranal and the NASA Spitzer Space Telescope, as well as other telescopes around the world, have now confirmed the existence of at least seven small orbiting the cool TRAPPIST-1. All the planets, labelled TRAPPIST-1b, c, d, e, f, g and h in order of increasing distance from their , have sizes similar to Earth.

Dips in the star’s light output caused by each of the seven planets passing in front of it (astronomy)—events known as transits—allowed the astronomers to infer information about their sizes, compositions and orbits. They found that at least the inner six planets are comparable in both size and temperature to the Earth.

Lead author Michaël Gillon of the STAR Institute at the University of Liège in Belgium is delighted by the findings: “This is an amazing planetary —not only because we have found so many planets, but because they are all surprisingly similar in size to the Earth!”

With just 8% the mass of the Sun, TRAPPIST-1 is very small in stellar terms—only marginally bigger than the planet Jupiter—and though nearby in the constellation Aquarius (The Water Carrier), it appears very dim. Astronomers expected that such dwarf stars might host many Earth-sized planets in tight orbits, making them promising targets in the hunt for extraterrestrial life, but TRAPPIST-1 is the first such system to be found.

Co-author Amaury Triaud expands: “The energy output from dwarf stars like TRAPPIST-1 is much weaker than that of our Sun. Planets would need to be in far closer orbits than we see in the Solar System if there is to be surface water. Fortunately, it seems that this kind of compact configuration is just what we see around TRAPPIST-1!”

The team determined that all the planets in the system are similar in size to Earth and Venus in the Solar System, or slightly smaller. The density measurements suggest that at least the innermost six are probably rocky in composition.

The planetary orbits are not much larger than that of Jupiter’s Galilean moon system, and much smaller than the orbit of Mercury in the Solar System. However, TRAPPIST-1’s small size and low temperature mean that the energy input to its planets is similar to that received by the in our Solar System; TRAPPIST-1c, d and f receive similar amounts of energy to Venus, Earth and Mars, respectively.

All seven planets discovered in the system could potentially have on their surfaces, though their orbital distances make some of them more likely candidates than others. Climate models suggest the innermost planets, TRAPPIST-1b, c and d, are probably too hot to support liquid water, except maybe on a small fraction of their surfaces. The orbital distance of the system’s outermost planet, TRAPPIST-1h, is unconfirmed, though it is likely to be too distant and cold to harbour liquid water—assuming no alternative heating processes are occurring. TRAPPIST-1e, f, and g, however, represent the holy grail for planet-hunting astronomers, as they orbit in the star’s .

These new discoveries make the TRAPPIST-1 system a very important target for future study. The NASA/ESA Hubble Space Telescope is already being used to search for atmospheres around the planets and team member Emmanuël Jehin is excited about the future possibilities: “With the upcoming generation of telescopes, such as ESO’s European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope , we will soon be able to search for water and perhaps even evidence of life on these worlds.”

This research was presented in a paper entitled “Seven temperate terrestrial planets around the nearby ultracool TRAPPIST-1″, by M. Gillon et al., to appear in the journal Nature.

See also here.

NASA FOUND SEVEN EARTH-SIZED PLANETS ORBITING NEARBY DWARF STAR All seven could potentially have water — and alien life. And it’s only a mere 39 light years away. [HuffPost]

The detection of a nearby solar system of potentially Earth-like exoplanets orbiting the star Trappist-1 has evoked widespread public interest and enthusiasm. Millions of people have read reports, watched videos and posted on social media about the seven worlds that might have liquid water on their surfaces: here.

Dutch astronomer boycotts USA because of Trump

Astronomer Ilse van Bemmel inspires young wannabe astronomer Merel in 2014

According to Dutch daily De Volkskrant today, Dutch astronomer Ilse van Bemmel has decided that for the time being she will not go to congresses in the USA.

Because of solidarity with everyone who is no longer welcome there. Whether they are refugees or scientists.

Asteroid namer after Dutch little boy with cancer

This 22 December 2016 music video is by Dutch singer Miss Montreal (pseudonym of Roos-Anne Hans).

She wrote this song ‘Tijn, deze is voor jou’ for and about a six-year-old boy called Tijn.

Tijn has terminal cancer and will probably die soon.

His last wish is to raise money for the Red Cross to help children suffering from pneumonia.

Doctors can’t cure Tijn’s cancer, but they can save pneumonia children’s lives for only four euros a child.

Tijn with red fingernails, ANP photo

This photo shows Tijn with red fingernails. He asked participants in the fundraising to also apply nail varnish to their fingers as a symbol.

Tijn expected to raise maybe 100 euros, saving 25 children.

However, today the amount has surpassed a million euros.

So, Tijn by now has saved 250,000 children’s lives.

Tijn’s parents are grateful to Miss Montreal for the song, which will remind them of their son after he will die.

From an astronomical newsletter, abound a recently named asteroid:

(6327) Tijn = 1991 GP1 Discovered 1991 Apr. 9 by E. F. Helin at Palomar. Named for Tijn Kolsteren from the Netherlands, who, at age 6 and diagnosed with an incurable brain tumor, raised over 2 million euros for the International Red Cross, as part of the Dutch charity radio program Serious Request 2016.

In recent years, rates of colorectal cancer cases and deaths in the United States rose among young and middle-aged adults, an American Cancer Society study of colorectal cancer trends between 2000 and 2014 finds: here.

Lunar eclipse in North America tonight

This video says about itself:

23 January 2017

A penumbral lunar eclipse will take place on February 10-11, 2017, the first of two lunar eclipses in 2017.

A penumbral eclipse is a tease, with none of the Moon entering Earth’s dark umbra as happens. But the one that occurs on February 10-11 will be about the best penumbral eclipse possible, as the Moon’s northern limb will miss the umbra by only about 100 miles (160 km). So the penumbral shading will be obvious.

This is a very deep penumbral eclipse. It has a penumbral eclipse magnitude of 0.9884 and a penumbral eclipse duration of 259.2 minutes.

During this type of eclipse the Moon will darken slightly but not completely.

The ideal spot to watch this penumbral eclipse is from Europe, Africa, Greenland and Iceland where the whole eclipse takes place at late night in a dark sky. For the most of of North America, the moon will be in eclipse at moonrise (sunset) on February 10 and will be obscured by evening twilight. In Asia, the eclipse will be obscured by morning twilight on February 11 and will be in eclipse at moonset (sunrise) February 11.

The penumbral lunar eclipse will be visible from Europe, most of Asia, Africa and most of North America.

Regions seeing, at least, some parts of the eclipse: Europe, much of Asia, Africa, North America, South America, Pacific, Atlantic, Indian Ocean, Arctic, Antarctica.

Clips, images credit: ESO, ESA/HUBBLE & NASA/JPL

From eNature Blog in the USA:

Watch The Moon Disappear Before Your Eyes—Don’t Miss This Friday’s Lunar Eclipse!

Posted on Tuesday, February 07, 2017 by eNature

There’s a penumbral lunar eclipse happening across all of North America the evening of Friday, February 10th.

The full moon will get noticeably less bright as it moves out of the sun’s direct light and into the Earth’s shadow shortly afternoon sundown on the East Coast.

What Exactly Is A Penumbral Eclipse?

The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra.

Within the umbra, there is no direct light from the sun. However, as a result of the Sun’s large size compared to the Earth, some solar illumination “bends” around the earth and is only partially blocked in the outer portion of the Earth’s shadow. That outer portion is called the penumbra.

Think of the shadow the Earth makes from the sun’s light as looking a bit like a dart board— with the dark umbra as the bulls eye and the less dark penumbra as the first circle surrounding the bulls eye.

A penumbral eclipse occurs when the moon passes through the Earth’s penumbra. The penumbra causes a subtle but clearly visible darkening of the moon’s surface.

A special type of penumbral eclipse is a total penumbral eclipse, during which the Moon lies exclusively within the Earth’s penumbra. Total penumbral eclipses are rare, and when these occur, that portion of the moon which is closest to the umbra can appear somewhat darker than the rest of the moon.

During Friday’s eclipse most, but not quite all, of the moon will enter the penumbra and observers should see a distinct darkening of the moon as the Earth’s shadow reduces the amount of sunlight hitting the moon.

It’s Safe And Easy To Observe

Unlike a solar eclipse, which can be viewed only from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth. A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place, due to the smaller size of the Moon’s shadow.

Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than the full moon.

It Starts Around Dinner Time

The eclipse will start to be noticeable a bit after 6:00 PM on the East coast (it actually begins at 5:32 PM) when the Moon’s leading edge enters Earth’s penumbra. You can do the math and see the timing is a little less friendly for readers on the West coast— but things should be be quite visible if the sky is clear.

The eclipse will last more than four hours and will be visible early Saturday in Europe, Africa and western Asia as well as North America.

Initially, the effect is not especially noticeable. You won’t start to see a dusky fringe along the Moon’s leading edge (known to astronomers as its “celestial east”) until the the moon intrudes about halfway across the penumbra. But keep an eye on the moon and your patience will be rewarded.

Watch Online If Your Local Weather Doesn’t Cooperate

If the weather isn’t so nice, or you just prefer to watch from the comfort of home, SLOOH will broadcast a live webcast. The webcast will start at 5:30 PM. EDT and you can watch it by clicking here.

There’s A Comet Out There Too!

Comet 45P will zip by Earth early Saturday morning. It will be an extremely close encounter as these things go, passing within 7.7 million miles (12.4 million kilometers) of Earth moving at 14.2 miles per second, or an eye-popping 51,120 mph.

The comet, glowing green, will be visible in the constellation Hercules. Binoculars and telescopes will help in the search as it will be quite difficult to see unassisted.

Astronomers have been tracking Comet 45P for the past couple of months. The icy ball — an estimated mile across — comes around every five years. It’s officially known as Comet 45P/Honda-Mrkos-Pajdusakova, named after the Japanese, Czech and Slovak astronomers who discovered it in 1948. The letter P stands for periodic, meaning it’s a recurring visitor to the inner solar system.

Regardless of the hour, you’ll not regret making time to catch one of nature’s best shows!

What are your plans for watching the eclipse? Or catching the comet? We’re planning to keep the kids up here…

Use Time and Date’s Eclipse Calculator to see when it’s visible in your town.

Supernovas and other astronomical news

This video says about itself:

Stephen Hawking – Supernovas

10 October 2011

Professor Stephen Hawking explains how these exploding stars produce all of the chemical elements which make up our bodies, and the world.

Supernova story continues, just like science journalism. By Elizabeth Quill, 12:45pm, February 8, 2017: here.

Observers caught these stars going supernova. Massive stellar explosions created these luminous, expanding shells of gas and dust. By Christopher Crockett, 11:47am, February 8, 2017: here.

30 years later, supernova 1987A is still sharing secrets. When the nearby star exploded, ‘the whole world got excited’. By Christopher Crockett, 8:00am, February 8, 2017: here.

When a nearby star goes supernova, scientists will be ready. Earth’s observatories hope to detect neutrinos and gravitational waves. By Emily Conover, 8:00am, February 8, 2017: here.

Middling black hole may be hiding in star cluster. Pulsar motion hints at extra source of strong gravity in 47 Tucanae. By Ashley Yeager, 1:00pm, February 8, 2017: here.

Hubble Finds Extrasolar Kuiper Belt Object Ripped Apart by White Dwarf: here.

Remembering Vera Rubin, a trailblazer at the telescope and beyond: here.