January 21, 2017

Supercell and Lightning over Texas

Supercell and Lightning over Texas

Texas, USA

Image Credit & Copyright: Mike Olbinski

The Carina Nebula

The Carina Nebula

This image taken by NASA's Spitzer Space Telescope shows the "South Pillar" region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope "busted open" this murky cloud to reveal star embryos (yellow or white) tucked inside finger-like pillars of thick dust (pink). Hot gases are green and foreground stars are blue. Not all of the newfound star embryos can be easily spotted.

Though the nebula's most famous and massive star, Eta Carinae, is too bright to be observed by infrared telescopes, the downward-streaming rays hint at its presence above the picture frame. Ultraviolet radiation and stellar winds from Eta Carinae and its siblings have shredded the cloud to pieces, leaving a mess of tendrils and pillars. This shredding process triggered the birth of the new stars uncovered by Spitzer.

Eta Carinae is a behemoth of a star, with more than 100 times the mass of our Sun. It is so massive that it can barely hold itself together. Over the years, it has brightened and faded as material has shot away from its surface. Some astronomers think Eta Carinae might die in a supernova blast within our lifetime.

Eta Carinae's home, the Carina Nebula, is located in the southern portion of our Milky Way galaxy, 10,000 light-years from Earth. This colossal cloud of gas and dust stretches across 200 light-years of space. Though it is dominated by Eta Carinae, it also houses the star's slightly less massive siblings, in addition to the younger generations of stars.

This image was taken by the infrared array camera on Spitzer. It is a three-color composite of invisible light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red).

Image Credit: NASA/JPL-Caltech/N. Smith (University of Colorado at Boulder)
Explanation from: http://www.spitzer.caltech.edu/images/1431-ssc2005-12a1-Carina-Nebula

Mars Ice Age

Mars Ice Age

This simulated view shows Mars as it might have appeared during the height of a possible ice age in geologically recent time.

Of all Solar System planets, Mars has the climate most like that of Earth. Both are sensitive to small changes in orbit and tilt. During a period about 2.1 million to 400,000 years ago, increased tilt of Mars' rotational axis caused increased solar heating at the poles. A new study using observations from NASA's Mars Global Surveyor and Mars Odyssey orbiters concludes that this polar warming caused mobilization of water vapor and dust into the atmosphere, and buildup of a surface deposit of ice and dust down to about 30 degrees latitude in both hemispheres. That is the equivalent of the southern Unites States or Saudi Arabia on Earth. Mars has been in an interglacial period characterized by less axial tilt for about the last 300,000 years. The ice-rich surface deposit has been degrading in the latitude zone of 30 degrees to 60 degrees as water-ice returns to the poles.

Image Credit: NASA/JPL/Brown University
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA04933

Lenticular Cloud over Dublin

Lenticular Cloud over Dublin

Dublin, Ireland
June 30, 2015

Image Credit: Omnisource5 via wikipedia.org

Saturn

Saturn

No Earth-based telescope could ever capture a view quite like this. Earth-based views can only show Saturn's daylit side, from within about 25 degrees of Saturn's equatorial plane. A spacecraft in orbit, like Cassini, can capture stunning scenes that would be impossible from our home planet.

This view looks toward the sunlit side of the rings from about 25 degrees (if Saturn is dominant in image) above the ring plane. The image was taken in violet light with the Cassini spacecraft wide-angle camera on October 28, 2016.

The view was obtained at a distance of approximately 810,000 miles (1.3 million kilometers) from Saturn. Image scale is 50 miles (80 kilometers) per pixel.

Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA20517

Pulsar PSR J1640-4631

Pulsar PSR J1640-4631

The blue dot in this image marks the spot of an energetic pulsar -- the magnetic, spinning core of star that blew up in a supernova explosion. NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, discovered the pulsar by identifying its telltale pulse -- a rotating beam of X-rays, that like a cosmic lighthouse, intersects Earth every 0.2 seconds.

The pulsar, called PSR J1640-4631, lies in our inner Milky Way galaxy about 42,000 light-years away. It was originally identified by as an intense source of gamma rays by the High Energy Stereoscopic System (H.E.S.S.) in Namibia. NuSTAR helped pin down the source of the gamma rays to a pulsar.

The other pink dots in this picture show low-energy X-rays detected by NASA's Chandra X-ray Observatory.

In this image, NuSTAR data is blue and shows high-energy X-rays with 3 to 79 kiloelectron volts; Chandra data is pink and shows X-rays with 0.5 to 10 kiloeletron volts.

The background image shows infrared light and was captured by NASA's Spitzer Space Telescope.

Image Credit: NASA/JPL-Caltech/SAO
Explanation from: https://www.nasa.gov/jpl/nustar/pia18836

January 20, 2017

Cotopaxi Volcano Eruption

Cotopaxi Volcano Eruption

Pichincha/Cotopaxi, Ecuador
October 8, 2015

Image Credit: Rodrigo Buendia

Atmosphere of Jupiter

Atmosphere of Jupiter

The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made of molecular hydrogen and helium in roughly solar proportions; other chemical compounds are present only in small amounts and include methane, ammonia, hydrogen sulfide and water. Although water is thought to reside deep in the atmosphere, its directly measured concentration is very low. The nitrogen, sulfur, and noble gas abundances in Jupiter's atmosphere exceed solar values by a factor of about three.

The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet. From lowest to highest, the atmospheric layers are the troposphere, stratosphere, thermosphere and exosphere. Each layer has characteristic temperature gradients. The lowest layer, the troposphere, has a complicated system of clouds and hazes, comprising layers of ammonia, ammonium hydrosulfide and water. The upper ammonia clouds visible at Jupiter's surface are organized in a dozen zonal bands parallel to the equator and are bounded by powerful zonal atmospheric flows (winds) known as jets. The bands alternate in color: the dark bands are called belts, while light ones are called zones. Zones, which are colder than belts, correspond to upwellings, while belts mark descending air. The zones' lighter color is believed to result from ammonia ice; what gives the belts their darker colors is not known with certainty. The origins of the banded structure and jets are not well understood, though two models exist. The shallow model holds that they are surface phenomena overlaying a stable interior. In the deep model, the bands and jets are just surface manifestations of deep circulation in Jupiter's mantle of molecular hydrogen, which is organized into cylinders.

The Jovian atmosphere shows a wide range of active phenomena, including band instabilities, vortices (cyclones and anticyclones), storms and lightning. The vortices reveal themselves as large red, white or brown spots (ovals). The largest two spots are the Great Red Spot (GRS) and Oval BA, which is also red. These two and most of the other large spots are anticyclonic. Smaller anticyclones tend to be white. Vortices are thought to be relatively shallow structures with depths not exceeding several hundred kilometers. Located in the southern hemisphere, the GRS is the largest known vortex in the Solar System. It could engulf two or three Earths and has existed for at least three hundred years. Oval BA, south of GRS, is a red spot a third the size of GRS that formed in 2000 from the merging of three white ovals.

Jupiter has powerful storms, often accompanied by lightning strikes. The storms are a result of moist convection in the atmosphere connected to the evaporation and condensation of water. They are sites of strong upward motion of the air, which leads to the formation of bright and dense clouds. The storms form mainly in belt regions. The lightning strikes on Jupiter are hundreds of times more powerful than those seen on Earth. However, there are so few, that the amount of lightning activity is comparable to Earth.

Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Eric Jorgensen
Explanation from: https://www.nasa.gov/image-feature/jpl/pia21377/jupiter-pearl-and-swirling-cloud-tops

Moon seen from the International Space Station

Moon seen from the International Space Station

ISS, Orbit of the Earth
June 21, 2016

Image Credit: NASA

January 19, 2017

Redoubt Volcano Eruption

Redoubt Volcano Eruption

Aleutian Range, Alaska, USA
April 16, 2009

Image Credit: Alaska Volcano Observatory

Hurricane Felix


This view of Hurricane Felix was taken from the Earth-oribting International Space Station by an Expedition 15 crewmember using a digital still camera equipped with a 28-70 mm lens set at 28 mm focal length on September 3, 2007 at 11:38:29 GMT. The ISS was located at the nadir point of 16.0 degrees north latitude and 84.0 degrees west longitude nearly over the coast of eastern Honduras when this image was taken. At approximately noon GMT, Hurricane Felix was near 14.2 degrees north latitude and 76.9 degees west longitude, about 260 miles (425 kilometers) south of Kingston Jamaica, and 425 miles (685 kilometers) east of Cabo Gracias a Dios on the Nicaragua/Honduras border, moving west at 21 miles per hour (33 kilometers per hour). The sustained winds were 165 miles per hour with higher gusts making it a category 5 on the Saffir-Simpson scale.

Image Credit: NASA
Explanation from: https://www.nasa.gov/mission_pages/station/multimedia/exp15_hurricane_felix.html

Molecular Cloud Orion A

Molecular Cloud Orion A

This spectacular new image is one of the largest near-infrared high-resolution mosaics of the Orion A molecular cloud, the nearest known massive star factory, lying about 1350 light-years from Earth. It was taken using the VISTA infrared survey telescope at ESO’s Paranal Observatory in northern Chile and reveals many young stars and other objects normally buried deep inside the dusty clouds.

The new image from the VISION survey (VIenna Survey In Orion) is a montage of images taken in the near-infrared part of the spectrum by the VISTA survey telescope at ESO’s Paranal Observatory in Chile. It covers the whole of the Orion A molecular cloud, one of the two giant molecular clouds in the Orion molecular cloud complex (OMC). Orion A extends for approximately eight degrees to the south of the familiar part of Orion known as the sword.

VISTA is the world’s largest dedicated survey telescope, and has a large field of view imaged with very sensitive infrared detectors, characteristics that made it ideal for obtaining the deep, high-quality infrared images required by this ambitious survey.

The VISION survey has resulted in a catalogue containing almost 800 000 individually identified stars, young stellar objects and distant galaxies, This represents better depth and coverage than any other survey of this region to date.

VISTA can see light that the human eye cannot, allowing astronomers to identify many otherwise hidden objects in the stellar nursery. Very young stars that cannot be seen in visible-light images are revealed when observed at longer infrared wavelengths, where the dust that shrouds them is more transparent.

The new image represents a step towards a complete picture of the star formation processes in Orion A, for both low and high mass stars. The most spectacular object is the glorious Orion Nebula, also called Messier 42 seen towards the left of the image. This region forms part of the sword of the famous bright constellation of Orion (The Hunter). The VISTA catalogue covers both familiar objects and new discoveries. These include five new young stellar object candidates and ten candidate galaxy clusters.

Elsewhere in the image, we can look into Orion A’s dark molecular clouds and spot many hidden treasures, including discs of material that could give birth to new stars (pre-stellar discs), nebulosity associated with newly-born stars (Herbig-Haro objects), smaller star clusters and even galaxy clusters lying far beyond the Milky Way. The VISION survey allows the earliest evolutionary phases of young stars within nearby molecular clouds to be systematically studied.

This impressively detailed image of Orion A establishes a new observational foundation for further studies of star and cluster formation and once again highlights the power of the VISTA telescope to image wide areas of sky quickly and deeply in the near-infrared part of the spectrum.

Image Credit: ESO/VISION survey
Explanation from: https://www.eso.org/public/news/eso1701/

January 18, 2017

Fox and Swiss 1.2-metre Leonhard Euler Telescope at ESO’s La Silla Observatory

Fox and Swiss 1.2-metre Leonhard Euler Telescope at ESO’s La Silla Observatory

Perched precariously on the edge of the habitable world, life manages to cling on. On the outskirts of the hot, dry Atacama Desert, this hardy South American grey fox has just awoken, stretching leisurely. These foxes are generally active during the night, making the most of the drop in temperature that comes with a respite from the hot Chilean Sun.

In the background there are other signs of life. This white dome houses the Swiss 1.2-metre Leonhard Euler Telescope, which is protected from the harsh conditions by its outer shell. As the skies grow darker at ESO’s La Silla Observatory another famously nocturnal species, the astronomer, wakes up, stretches, and gets ready to scan the skies with buzzing and whirring technology.

Image Credit: ESO/M. Tewes
Explanation from: https://www.eso.org/public/images/potw1406a/

Spiral Galaxy NGC 3521

Spiral Galaxy NGC 3521

This picture of the nearby galaxy NGC 3521 was taken using the FORS1 instrument on ESO’s Very Large Telescope, at the Paranal Observatory in Chile. The large spiral galaxy lies in the constellation of Leo (The Lion), and is only 35 million light-years distant. This picture was created from exposures taken through three different filters that passed blue light, yellow/green light, and near-infrared light. These are shown in this picture as blue, green, and red, respectively.

Image Credit: ESO/O. Maliy
Explanation from: https://www.eso.org/public/images/eso1129a/

Globular Cluster Palomar 1

Globular Cluster Palomar 1

The NASA/ESA Hubble Space Telescope has captured a clear view of the unusual globular cluster Palomar 1, whose youthful beauty is a puzzle for astronomers. This faint and sparse object is very different from the more familiar brilliant and very rich globular clusters and had to wait until 1954 for its discovery by George Abell on photographs from the Palomar Schmidt telescope.

Globular clusters are tightly bound conglomerations of stars, which are found in the outer reaches of the Milky Way, in its so-called halo. They are amongst the oldest objects in a galaxy, containing very old stars and no gas, which means there is no possibility of newborn stars introducing some fresh blood into the cluster.

However, at 6.3 to 8 billion years old, Palomar 1 is a youngster in globular cluster terms — little more than half the age of most the other globulars in our Milky Way, which formed during our galaxy’s violent early history. However, astronomers suspect that globular youngsters, such as Palomar 1, formed in a more sedate manner. Possibly a gas cloud meandered around in the Milky Way’s halo until a trigger kick-started star formation. Another possibility is that the Milky Way captured the stellar group; perhaps it was adrift in the Universe before it was gravitationally attracted to our galaxy, or maybe it had a violent beginning after all and is the remnant of a dwarf galaxy that was devoured by the Milky Way.

Behind the sparsely populated Palomar 1 several background galaxies are seen and a few nearby bright foreground Milky Way stars are also visible. Together with Palomar 1 these objects make up an attractive “family portrait”.

This picture was created from images taken with the Wide Field Channel of the Advanced Camera for Surveys. Images through orange (F606W, coloured blue) and near-infrared (F814W, coloured red) filters were combined. The exposure times were 1965 s per filter and the field of view is 3.0 arcminutes across.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1104a/

Aurora over Mestervik

Aurora over Mestervik

Mestervik, Balsfjord, Troms, Norway
September 30, 2014

Image Credit: Yannis Behrakis

The region around the massive star IRS2

The region around the massive star IRS2

Colour composite image of the central part of the stellar cluster RCW 38, around the young, massive star IRS2, taken with the NACO adaptive optics instrument attached to ESO's Very Large Telescope. Thanks to this image, astronomers were able to discover that IRS2 is in fact a twin system composed of two almost equally massive stars. The astronomers also found a handful of protostars – the faintly luminous precursors to fully realised stars – and dozens of other candidate stars that have eked out an existence here despite the powerful ultraviolet light radiated by IRS2.

The image is based on near-infrared data taken through three different filters (J, H and K). The field of view is about 1 arcminute across.

Image Credit: ESO
Explanation from: http://eso.org/public/images/eso0929a/

Earth

Earth seen from the International Space Station

ISS, Orbit of the Earth
September 2016

Image Credit: NASA/ESA