distant-traveller:

Orion’s cradle

Cradled in glowing hydrogen, stellar nurseries in Orion lie at the edge of a giant molecular cloud some 1,500 light-years away. This breath-taking view spans about 13 degrees across the center of the well-known constellation with the Great Orion Nebula, the closest large star forming region, just right of center. The deep mosaic also includes (left of center), the Horsehead Nebula, the Flame Nebula, and Orion’s belt stars. Image data acquired with a hydrogen alpha filter adds other remarkable features to this wide angle cosmic vista — pervasive tendrils of energized atomic hydrogen gas and portions of the surrounding Barnard’s Loop. While the Orion Nebula and belt stars are easy to see with the unaided eye, emission from the extensive interstellar gas is faint and much harder to record, even in telescopic views of the nebula-rich complex.

Image credit: Tony Hallas

stellar-indulgence:

Soul Nebula

stellar-indulgence:

Orion the Hunter

Orion is one of the most easily identifiable constellations in the sky. The three stars on Orion’s belt, as well as the four (limbs) enshrouding them, seem to leap out at you once you know what to look for. His shoulder is marked by the red supergiant Betelgeuse (literally “armpit of the central one” in Arabic), and his left leg is marked by the blue-white supergiant Rigel.

But do you see that little pink blob just below the belt? That’s no star at all, that’s the Orion Nebula, one of the only nebulae in the whole sky visible to the naked eye. Even through a small telescope, it’s a beauty to behold.

For the Observer

Alpha Orionis, Betelguese (05h52.5m +07° 24’)means “the armpit of the giant. It is a huge swollen red supergiant 650 light years distant. The star is a class M2 of magnitude 0.8, and it expands and contracts by 20 % of its diameter. These variations are actually quite spectacular and the diameter ranges from between 700 and 1000 times that of our Sun! Betelguese has a surface temperature of about 3400 K. Because massive stars burn their fuel at a much faster rate, Betelguese has an estimated lifetime of only 5 to 10 million years (as opposed to our Sun’s lifetime of 10 billion years.) Bigger is not always better!

Beta Orionis, Rigel (05h15m -08 12’) the “left foot of Orion” is a 0.1 magnitude class B8 blue supergiant about 800 light years distant. Rigel’s luminosity is about 55,000 times greater than our Sun. If Rigel was as close as Sirius, it would appear as bright as a crescent moon! Rigel has a 6.7 magnitude bluish companion that is believed to by a physical binary.

Gamma Orionis, Bellatrix (05h25m +06° 21’) means “female warrior.” Bellatrix is a class B2 blue supergiant with a magnitude of 1.6. The star is 300 light years distant. It is a relatively young star, probably less than 10 million years old. Bellatrix appears to be surrounded by a shell of expanding gas indicating the star is ejecting some of its atmosphere into space.

Delta Orionis, Mintaka (05h32m -00° 18’) means “the belt” which is where this star is located in Orion. Mintaka has a magnitude of 2.2 and is a blue giant class B0 star. Its distance is 800 light years away. Mintaka is both a visusl and spectroscopic binary. The spectroscopic companion is a blue star, the visual companion is 52 arcseconds from Mintaka. There is a bluish 6.7 magnitude companion to Mintaka. The stars form a physical pair with a separation of about 0.5 light years.

Kappa Orionis, Saiph (05h48m -09° 40’) is a 2.1 magnitude class B0.5 blue supergiant. The star is 2,000 light years distant.

M42 (NGC 1976) The “Great Nebula in Orion.”(05h32.9m -05° 25) This beautiful gaseous nebula can be found in the sword of Orion, and can be seen is a pair of binoculars. In telescopes, it is breathtaking! This glowing cloud shines by the light of stars embedded within. M42 is a stellar nursery, where star formation is taking place. The nebula is about 1600 light years distant and about 30 light years accross.

M43 (NGC1982) (05h33.1m -05° 18’) This is actually a detached portion of the Great Nebula M42. It has a bright class O bluish central star.

NGC2194 (06h11m +12° 50’) Cluster of about 100 stars with an overall magnitude of about 9.

NGC2169 (06h05.7m +13° 58’) Small compact cluster. Overall magnitude of 8.

Mythology

Orion is the legendary great hunter of the Greek mythology. It was said he was the most beautiful of men and the most skillfull of hunters. Unfortunately Orion accepted this praise with utter confidence it was true, and then some. He began boasting of his skills, claiming to have total superiouity over all creatures. Quite naturally, this annoyed the gods that be and they decided to punish him for his greatly inflated ego. Firmly believing in capitol punishment, the gods sent Scorpius, the scorpion was to earth to sting Orion’s foot, and kill him. Diana, an admirer of Orion (and his ego) implored the gods to place the great hunter in the sky to remember him by. This they agreed to, so long as they also placed the scorpion there to warn against such nasty crimes as ego. In Orion’s last dying breatls he begged not to be placed near the scorpion. And so, Orion dominates the winter skies while Scorpius’ domain is the summer skies.

Sources: 1, 2, 3 Top image credit: Jim Delillo

thescienceofreality:

NASA’s Big Mars Rover Makes First Use of its Brush.

“ NASA’s Mars rover Curiosity has completed first-time use of a brush it carries to sweep dust off rocks. 

Nearing the end of a series of first-time uses of the rover’s tools, the mission has cleared dust away from a targeted patch on a flat Martian rock using the Dust Removal Tool. 

The tool is a motorized, wire-bristle brush designed to prepare selected rock surfaces for enhanced inspection by the rover’s science instruments. It is built into the turret at the end of the rover’s arm. In particular, the Alpha Particle X-ray Spectrometer and the Mars Hand Lens Imager, which share the turret with the brush and the rover’s hammering drill, can gain information after dust removal that would not be accessible from a dust-blanketed rock. 

Choosing an appropriate target was crucial for the first-time use of the Dust Removal Tool. The chosen target, called “Ekwir_1,” is on a rock in the “Yellowknife Bay” area of Mars’ Gale Crater. The rover team is also evaluating rocks in that area as potential targets for first use of the rover’s hammering drill in coming weeks.”

Images of the brushed area on Ekwir are online here and here.

Continue…

(via sagansense)

sagansense:

geneticist:

After the Pluto’s demotion from planet-status, astrophysicist Neil DeGrasse Tyson received hate mail from thousands of elementary school children. Images via PBS

Only in America. Fact.

(via sagansense)

stellar-indulgence:

Heart Nebula

scinerds:

NGC 1999

Image Credit: Z. Levay (STScI/AURA/NASA), T.A. Rector (University of Alaska Anchorage) and H. Schweiker (NOAO/AURA/NSF)

This wide-field panorama of star formation was captured with the National Science Foundation’s Mayall 4-meter telescope on Kitt Peak. Located in the constellation of Orion (the Hunter), the image show a portion of one of Orion’s giant molecular clouds (known as “Orion A”) where new stars are forming.

stellar-indulgence:

Alcyoneus Nebula by tsarye

sagansense:

Distance from Earth to Mars
Sending spacecraft to Mars is all about precision. It’s about blasting off from Earth with a controlled explosion, launching a robot into space in the direction of the Red Planet, navigating the intervening distance between our two planets, and landing with incredible precision. This intricate and complicated manoeuvre means knowing the exact distance from Earth to Mars. And unfortunately, this distance is always changing.

How Far is Mars From Earth?
Both Earth and Mars are following elliptical orbits around the Sun, like two cars travelling at different speeds on two different racetracks. Sometimes the planets are close together, and other times they’re on opposite sides of the Sun. And although they get close and far apart, those points depend on where the planets are on their particular orbits. So, the Earth Mars distance is changing from minute to minute.

A Quick Explainer on Orbital Mechanics
The planets don’t follow circular orbits around the Sun, they’re actually travelling in ellipses. Sometimes they’re at the closest point to the Sun (called perihelion), and other times they’re at the furthest point from the Sun (known as aphelion). To get the closest point between Earth and Mars, you need to imagine a situation where Earth and Mars are located on the same side of the Sun. Furthermore, you want a situation where Earth is at aphelion, at its most distant point from the Sun, and Mars is at perihelion, the closest point to the Sun.

When Earth and Mars are closest

When Earth and Mars reach their closest point, this is known as opposition. It’s the time that Mars appears as a bright red star of the sky; one of the brightest objects, rivalling the brightness of Venus or Jupiter. There’s no question Mars is bright and close, you can see it with your own eyes.

And theoretically at this point, Mars and Earth will be only 54.6 million kilometers from each other. But here’s the thing, this is just theoretical, since the two planets haven’t been this close to one another in recorded history. The last known closest approach was back in 2003, when Earth and Mars were only 56 million kilometers apart. And this was the closest they’d been in 50,000 years.

Need that in miles? The closest possible distance from Earth to Mars in miles is 33.9 million miles.

Here’s a list of Mars Oppositions from 2007-2020 (source)

Dec. 24, 2007 – 88.2 million km (54.8 million miles)
Jan. 29, 2010 – 99.3 million km (61.7 million miles)
Mar. 03, 2012 – 100.7 million km (62.6 million miles)
Apr. 08, 2014 – 92.4 million km (57.4 million miles)
May. 22, 2016 – 75.3 million km (46.8 million miles)
Jul. 27. 2018 – 57.6 million km (35.8 million miles)
Oct. 13, 2020 – 62.1 million km (38.6 million miles)
*2018 should be a very good year, with a Mars looking particularly bright and red in the sky.

When Earth and Mars are furthest apart

On the opposite end of the scale, Mars and Earth can be 401 million km apart (249 million miles) when they are in opposition and both are at aphelion. The average distance between the two is 225 million km.

When Mars is Close, You’re Go For Launch
Mars and Earth reach this closest point to one another approximately every two years. And this is the perfect time to launch a mission to the Red Planet. If you look back at the history of launches to Mars, you’ll notice they tend to launch about every two years.

Here’s an example of recent Missions to Mars, and the years they launched:

MER-A Spirit – 2003
MER-B Opportunity – 2003
Mars Reconnaissance Orbiter – 2005
Phoenix – 2007
Fobos-Grunt – 2011
MSL Curiosity – 2011
*See the trend? Every two years. They’re launching spacecraft when Earth and Mars reach their closest point.

Spacecraft don’t launch directly at Mars; that would use up too much fuel. Instead, spacecraft launch towards the point that Mars is going to be in the future. They start at Earth’s orbit, and then raise their orbit until they intersect the orbit of Mars; right when Mars is at that point. The spacecraft can then land on Mars or go into orbit around it. This journey takes about 250 days.

Communicating with Mars
With these incredible distances between Earth and Mars, scientists can’t communicate with their spacecraft in real time. Instead, they need to wait for the amount of time it takes for transmissions to travel from Earth to Mars and back again.

When Earth and Mars are at their theoretically closest point of 54.6 million km, it would take a signal from Earth about 3 minutes to make the journey, and then another 3 minutes for the signals to get back to Earth. But when they’re at their most distant point, it takes more like 21 minutes to send a signal to Mars, and then another 21 minutes to receive a return message.

This is why the spacecraft sent to Mars are highly autonomous. They have computer systems on board that allow them to study their environment and avoid dangerous obstacles completely automatically, without human intervention.

The distance from Earth to Mars is the main reason that there has never been a manned flight to the Red Planet. Scientists around the world are working on ways to shorten the trip with the goal of sending a human into Martian orbit within the next decade.
This website lists every Mars opposition time, from recent past all the way in the far future. You can also use NASA’s Solar System Simulator to see the current position of any object in the Solar System.

distant-traveller:

Blazing bristlecone

Image credit: Tom Lowe

distant-traveller:

The Hunter’s stars

Begirt with many a blazing star, Orion, the Hunter, is one of the most easily recognizable constellations. In this night skyscape from January 15, the hunter’s stars rise in the northern hemisphere’s winter sky, framed by bare trees and bounded below by terrestrial lights around Lough Eske (Lake of Fish) in County Donegal, Ireland. Red giant star Betelgeuse is striking in yellowish hues at Orion’s shoulder above and left of center. Rivaling the bright red giant, Rigel, a blue supergiant star holds the opposing position near Orion’s foot. Of course, the sword of Orion hangs from the hunter’s three belt stars near picture center, but the middle star in the sword is not a star at all. A slightly fuzzy pinkish glow hints at its true nature, a nearby stellar nursery visible to the unaided eye known as the Orion Nebula.

Image credit: Brendan Alexander

thescienceofreality:

Barnard Stares at NGC 2170 

Image Credit & Copyright: John Davis

“A gaze across a cosmic skyscape, this telescopic mosaic reveals the continuous beauty of things that are. The evocative scene spans some 6 degrees or 12 Full Moons in planet Earth’s sky. At the left, folds of red, glowing gas are a small part of an immense, 300 light-year wide arc. Known as Barnard’s loop, the structure is too faint to be seen with the eye, shaped by long gone supernova explosions and the winds from massive stars, and still traced by the light of hydrogen atoms. Barnard’s loop lies about 1,500 light-years away roughly centered on the Great Orion Nebula, a stellar nursery along the edge of Orion’s molecular clouds. But beyond lie other fertile star fields in the plane of our Milky Way Galaxy. At the right, the long-exposure composite finds NGC 2170, a dusty complex of nebulae near a neighboring molecular cloud some 2,400 light-years distant.”

(Source: gayasaurousrex94, via sagansense)

Earth in HD

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subatomiconsciousness:

The new image from the European Southern Observatory shows Lupus 3, which lies about 600 light-years from Earth in the constellation of Scorpius. The section shown here is about five light-years across. 
Lupus 3 is a stellar nursery. The dark, cloudy shape on the left shows where new stars are forming. The bright patch is new stars that have emerged from their dusty nursery. 
It is likely that the Sun formed in a similar star formation region more than four billion years ago.