Tag: Astronomy

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Move across Helix Nebula

Move across Helix Nebula

A counterclockwise zoom and rotation sequence of the Helix Nebula. The Hubble’s Advanced Camera for Surveys image of the Helix Nebula reveals thousands of comet-like filaments embedded along the inner rim of the nebula that point back towards the central star.

► Credit: NASA, The Hubble Helix Team and G. Bacon (STScI)

► The animation below comes from a NASA video “Move across Helix Nebula”, that you can watch here>>

http://hubblesite.org/newscenter/archive/releases/2003/11/video/c/

Helix Nebula, also known as NGC 7293, located at a distance of about 700 light-years in the constellation Aquarius, is one of the nearest planetary nebulae to Earth.

This bright and large planetary nebula was discovered by Karl Ludwig Harding, probably before 1824.

It is similar in appearance to the Cat’s Eye Nebula and the Ring Nebula, whose size, age, and physical characteristics are similar to the Dumbbell Nebula, varying only in its relative proximity and the appearance from the equatorial viewing angle.

The Helix Nebula has sometimes been referred to as the “Eye of God” in pop culture, as well as the “Eye of Sauron”.

The Helix Nebula is an example of a planetary nebula, or ‘nebula’ formed at the end of a star’s evolution. Gases from the star in the surrounding space appear, from our vantage point, as if we are looking down a helix structure. The remnant central stellar core, known as a planetary nebula nucleus or PNN, is destined to become a white dwarf star. The observed glow of the central star is so energetic that it causes the previously expelled gases to brightly fluoresce.

The Helix Nebula was also the first planetary nebula discovered to contain cometary knots. More than 20,000 of them are estimated to be in this interesting nebula. Their origins are still not well understood.

Further reading and references

► https://en.wikipedia.org/wiki/Helix_Nebula

► http://apod.nasa.gov/apod/ap080413.html

► http://www.noao.edu/jacoby/pn_gallery.html

► http://hubblesite.org/newscenter/archive/releases/1996/13/image/a/

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Farewell Lutetia | European Space Agency

 

Originally shared by Friends of NASA

Farewell Lutetia | European Space Agency

This ethereal image shows a stunning sliver of large main-belt asteroid Lutetia from the viewpoint of ESA’s Rosetta spacecraft, taken as Rosetta passed by on its 10-year voyage towards comet 67P/Churyumov–Gerasimenko.

This week marks four years since Rosetta flew by this ancient rocky body, on July 10, 2010. As the spacecraft swung past Lutetia it snapped hundreds of high-resolution photographs with its Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS) as well as obtaining valuable spectra, and maps of the surface temperature using other instruments.

This image was taken as Rosetta had passed its closest approach, at just under 3170 km from Lutetia’s surface, and was beginning its journey away from the asteroid.

As a result of this flyby, astronomers have been able to characterise Lutetia, viewing the wide range of craters and geological features scarring the asteroid’s surface and gauging its mass and volume–and thus density and composition. These measurements showed that Lutetia is primordial, likely having formed just under 4 billion years ago during the very early phases of the Solar System.

This asteroid is one of just two that Rosetta has closely flown past, the other being asteroid Steins in 2008.

Rosetta was launched in 2004 and, after 10 years in space, will finally rendezvous with its target comet in August. It will study the comet’s surface, dust and gases in unprecedented detail, deploy a lander onto its surface, and follow the comet for over a year as it orbits around the Sun.

Credit: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Release Date: 07/07/2014 

European Space Agency, ESA 

 #Space   #Asteroid    #Spacecraft