BTW: We have been hit with a pretty sizable winter storm with up to 50 cm of wet snow in the area (30 cm right here) and almost all of it still clinging to trees. What will happen when the wind comes up is unknown. I can make power, hope the internet stays up!
Not a new image but always fun to look at is the Egg Nebula. I always think of ripples in a pond produced by tossing a pebble in and in a way it is. ars
Planetary nebulas have nothing much to do with planets, rather they are how stars like our own sun will end their active life cycles. Planetary nebulas are varied in how they present themselves but all are beautiful sights to see.
This colourful image shows a cosmic lighthouse known as the Egg Nebula, which lies around 3000 light-years from Earth. The image, taken with the NASA/ESA Hubble Space Telescope, has captured a brief but dramatic phase in the life of a Sun-like star.
The Egg Nebula is a ‘preplanetary nebula’. These objects occur as a dying star’s hot remains briefly illuminates material it has expelled, lighting up the gas and dust that surrounds it.
These objects will one day develop into planetary nebulas which, despite the name, have nothing at all to do with planets. They gained their rather misleading title because when they were discovered in the 18th century they resembled planets in our Solar System when viewed through a telescope.
Although the dying star is hidden behind the thick dust lane that streaks down the centre of this image, it is revealed by the four lighthouse-like beams clearly visible through the veil of dust that lies beyond the central lane.
The light beams were able to penetrate the central dust lane due to paths carved out of the thick cloud by powerful jets of material expelled from the star, although the cause of these jets is not yet known.
The concentric rings seen in the less dense cloud surrounding the star are due to the star ejecting material at regular intervals – typically every hundred years – during a phase of the star’s evolution just prior to this preplanetary nebula phase. These dusty shells are not usually visible in these nebulas, but when they are it provides astronomers with a rare opportunity to study their formation and evolution. Continue reading →
A nice video of Mount Tavurvur erupting in Papua New Guinea, I believe this is on the island of New Britain. Don’t be too tempted to close the ad banner that pops up, I missed the very start of the eruption doing that.
Check out the blast wave above the volcano too.
When I was looking at the different versions of this on YouTube there was already the doom predictions, because after all there is this volcano and the one in Iceland at the same time, it just has to mean something bad right?. Just so you know, volcanic eruptions aren’t really that uncommon and I wouldn’t assign any particular global doom to the fact these two just happen to be active at the same time.
I was looking all over for a graphic on the Mars encounter last Thursday and NASA published this on Friday. Great timing! So now I need to figure out if the comet might be visible with a telescope. Could be, the moon won’t be a factor and Mars should be visible for a time after sunset. I just need to upload the ephemeris for Siding Spring into Stellarium.
One thing I will be able to see (and so will you) on that night is Venus and Spica very close together — easy to see too. More about that later on.
NASA on the visit:
NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.
The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.
Nice picture from NASA of the Super Moon setting over the Orbital Science Antares rocket with the Cygnus cargo ship ready for flight. See the original here (suitable for a nice desktop).
The Antares did launch successfully today. Nice launch too, although I admit to doing the same thing as the last launch: as the Antares first leaves the pad, I’m saying ” come on, come on – get up there you can do it”. There is a (short) time where it looks like the rocket is just able to lift itself, a short time, yes but long enough to get me wondering! Here’s a replay if you missed it. So far everything looks great with Cygnus.
Now hopefully you got a look at the nice full moon we had. It was really quite spectacular. This full moon was just one of three in a row. Yes! August and September will also have the perigee “Supermoons”.
Summer for some (including me) and winter for others “officially” arrived at 10:51 UTC (06:51 EDT).
Funny, I seem to notice the morning shadows as much as the extra daylight. I think it is because the sun rises northeasterly enough to clear the mountains earlier than normal thank to hitting a low spot in the hills. This means the sun is at a lower angle, thus longer shadows and it does this for a very short time – only a couple weeks. “Normally” the sun has to be pretty high before the sun hits here, being relatively close to the mountains. It’s light of course but direct sunlight has to move in from the west as the Sun climbs.
At any rate I kind of liked this time lapse from Anchorage Alaska. I should try this, maybe Sunday. An image every half hour? I bet I can find some weather cams to capture image frames from. The video was from 2012 and runs from 1930 on 21 Jun to 00:40 on 24 Jun.
NASA’s Low-Density Supersonic Decelerator (LDSD) launch has been put off until some other time after 14 June (Saturday) due to weather.
Launching is not as easy as just waiting out the weather. This from NASA’s LDSD Launch Status Updates: “NASA will research range availability for the coming weeks and the costs associated with extending the test flight period for launching LDSD’s high-altitude balloon and test vehicle, with programmatic decisions required to proceed.”.
This supercomputer simulation shows one of the most violent events in the universe: a pair of neutron stars colliding, merging and forming a black hole.
A neutron star is the compressed core left behind when a star born with between eight and 30 times the sun’s mass explodes as a supernova. Neutron stars pack about 1.5 times the mass of the sun — equivalent to about half a million Earths — into a ball just 12 miles (20 km) across.
As the simulation begins, we view an unequally matched pair of neutron stars weighing 1.4 and 1.7 solar masses. They are separated by only about 11 miles, slightly less distance than their own diameters. Redder colors show regions of progressively lower density.
As the stars spiral toward each other, intense tides begin to deform them, possibly cracking their crusts. Neutron stars possess incredible density, but their surfaces are comparatively thin, with densities about a million times greater than gold. Their interiors crush matter to a much greater degree densities rise by 100 million times in their centers. To begin to imagine such mind-boggling densities, consider that a cubic centimeter of neutron star matter outweighs Mount Everest.
By 7 milliseconds, tidal forces overwhelm and shatter the lesser star. Its superdense contents erupt into the system and curl a spiral arm of incredibly hot material. At 13 milliseconds, the more massive star has accumulated too much mass to support it against gravity and collapses, and a new black hole is born. The black hole’s event horizon — its point of no return — is shown by the gray sphere. While most of the matter from both neutron stars will fall into the black hole, some of the less dense, faster moving matter manages to orbit around it, quickly forming a large and rapidly rotating torus. This torus extends for about 124 miles (200 km) and contains the equivalent of 1/5th the mass of our sun.
Scientists think neutron star mergers like this produce short gamma-ray bursts (GRBs). Short GRBs last less than two seconds yet unleash as much energy as all the stars in our galaxy produce over one year.
The rapidly fading afterglow of these explosions presents a challenge to astronomers. A key element in understanding GRBs is getting instruments on large ground-based telescopes to capture afterglows as soon as possible after the burst. The rapid notification and accurate positions provided by NASA’s Swift mission creates a vibrant synergy with ground-based observatories that has led to dramatically improved understanding of GRBs, especially for short bursts.
By 7 milliseconds, tidal forces overwhelm and shatter the lesser star. Its superdense contents erupt into the system and curl a spiral arm of incredibly hot material. At 13 milliseconds, the more massive star has accumulated too much mass to support it against gravity and collapses, and a new black hole is born. The black hole’s event horizon — its point of no return — is shown by the gray sphere. While most of the matter from both neutron stars will fall into the black hole, some of the less dense, faster moving matter manages to orbit around it, quickly forming a large and rapidly rotating torus. This torus extends for about 124 miles (200 km) and contains the equivalent of 1/5th the mass of Continue reading →