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NASA’s Hubble Space Telescope (HST) has discovered the smallest object ever seen (in visible light) in the Kuiper Belt, a region of the Solar System beyond the planets extending from the orbit of Neptune (at 30 AU) to approximately 55 AU from the Sun. The discovered object is estimated to be only 1 km across. The smallest Kuiper Belt Object (KBO) seen previously in reflected sunlight had the size of roughly 50 km. Observed at the distance of 6.76 billion km (45.2 AU), an object 1 km in diameter is about 100 times dimmer than those the HST can detect directly.

Artist's impression of a small Kuiper Belt Object (KBO) occulting a star - Credit: NASA, ESA, and G. Bacon (STScI)

This particular KBO was actually discovered indirectly, in the data from Hubble’s Fine Guidance Sensors (FGS), which provides high-precision navigational information to the observatory’s attitude control systems by looking at select guide stars for pointing. The extreme precision of FGS instruments can reveal the effects of a small object passing in front of a star. This would cause a brief occultation and diffraction signature in the FGS data as the light from the background guide star is bent around the intervening foreground KBO.

Hilke Schlichting of the California Institute of Technology and her collaborators reported the discovery of such a signature after an analysis of FGS data from 50,000 guide starts taken over the period of 4.5 years. They discovered a single 0.3 second long occultation event. The duration of the occultation was used to estimate the object’s distance and the amount of dimming provided means for determining its size.

The Hubble Space Telescope captured the most detailed view of the largest stellar nursery in our local galactic neighborhood. The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula (also known as Tarantula Nebula or NGC 2070), a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. R136 has an estimated mass of the cluster is 450,000 solar masses suggesting it will likely become a globular cluster in the future.

Despite the distance of about 180,000 light years, the nebula is an extremely luminous non-stellar objects. Its luminosity is so great that if it were as close to Earth as the Orion Nebula, the Tarantula Nebula would cast shadows. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus. Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These stars are destined to end their lives in a cataclysmic explosion becoming one of the most luminous objects in the universe. The closest supernova observed since the invention of the telescope, Supernova 1987A, occurred in the outskirts of the Tarantula Nebula.

30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC) - Credit: NASA, ESA, F. Paresce (INAF-IASF, Bologna, Italy), R. O'Connell (University of Virginia, Charlottesville), and the Wide Field Camera 3 Science Oversight Committee

The image above, taken in ultraviolet, visible, and red light by Hubble’s Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the birth and evolution of stars in the universe. The Hubble observations were taken Oct. 20-27, 2009. The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.

NASA’s Hubble Space Telescope has made the deepest image of the universe ever taken in near-infrared light. The faintest and reddest objects in the image are galaxies that formed 600 million years after the Big Bang. No galaxies have been seen before at such early times. The new deep view also provides insights into how galaxies grew in their formative years early in the universe’s history.

Hubble's Deepest View of Universe Unveiling Never-Before-Seen Galaxies taken with the new WFC3/IR camera on Hubble in late August 2009 during a total of four days of pointing for 173,000 seconds of total exposure time - Source: NASA, ESA, G. Illingworth (UCO/Lick Observatory and the University of California, Santa Cruz), R. Bouwens (UCO/Lick Observatory and Leiden University), and the HUDF09 Team

The image was taken in the same region as the Hubble Ultra Deep Field (HUDF), which was taken in 2004 and is the deepest visible-light image of the universe. Hubble’s newly installed Wide Field Camera 3 (WFC3) collects light from near-infrared wavelengths and therefore looks even deeper into the universe, because the light from very distant galaxies is stretched out of the ultraviolet and visible regions of the spectrum into near-infrared wavelengths by the expansion of the universe.

The photo was taken with the new WFC3/IR camera on Hubble in late August 2009 during a total of four days of pointing for 173,000 seconds of total exposure time. Infrared light is invisible and therefore does not have colors that can be perceived by the human eye. The colors in the image are assigned comparatively short, medium, and long, near-infrared wavelengths (blue, 1.05 microns; green, 1.25 microns; red, 1.6 microns). The representation is “natural” in that blue objects look blue and red objects look red. The faintest objects are about one-billionth as bright as can be seen with the naked eye.

Source: NASA

Composite image of the Crab Nebula using data from three of NASA's Great Observatories. - Source: X-ray: NASA/CXC/SAO/F.Seward; Optical: NASA/ESA/ASU/J.Hester & A.Loll; Infrared: NASA/JPL-Caltech/Univ. Minn./R.Gehrz

The amazing picture of the 1054 supernova remnant above (1920×1080 version) is a composite of NASA’s three great space observatories: the Hubble Space Telescope (red and yellow), the Spitzer Space Telescope (purple) and the Chandra X-Ray Observatory (blue).

The X-ray image is smaller than the others because extremely energetic electrons emitting X-rays radiate away their energy more quickly than the lower-energy electrons emitting optical and infrared light. Along with many other telescopes, Chandra has repeatedly observed the Crab Nebula over the course of the mission’s lifetime. The Crab Nebula is one of the most studied objects in the sky, truly making it a cosmic icon.

You may have seen the Hubble Ultra Deep Field (HUDF) photo before – it is a photo of a clear patch of sky that shows over 10,000 galaxies. It is often called the most important image ever taken because it allowed scientists to estimate that there are over a 100 billion to 1 trillion galaxies in the universe.

This view of nearly 10,000 galaxies is the deepest visible-light image of the cosmos. Called the Hubble Ultra Deep Field, this galaxy-studded view represents a "deep" core sample of the universe, cutting across billions of light-years - Photo Credit: NASA, ESA, S. Beckwith (STScI) and the HUDF Team

Earlier this month a 3D animation rendered using the measured redshift of all 10,000 galaxies in the Hubble Ultra Deep Field image hit YouTube:

Quite an impressive view, isn’t it? Well … here is another one (a tiny part of the huge image below). It is a rarely seen before image that is perhaps a hundred times larger (here’s a link to the BitTorrent of the image [180 MB]) than the HUDF and thus not widely circulated.

In a way, this view is more special because rather than a static photo, it actually is an interactive composite made using the OpenZoom technology, similar to Google Maps. You can pan the “map” using the arrows on your keyboard (or by dragging its parts with your mouse). +/- (or the wheel button) can be used to zoom in and out. Also, you can press ‘F’ to enter the full-screen mode and ‘H’ to return to the original view.

The author of this composite also made available a similar view of the Orion Nebula.

May 11, 2009 at 18:01:56 UT – NASA successfully launched the space shuttle Atlantis on the fifth and final service mission to the Hubble Space Telescope (HST). Due to an anomaly aboard the telescope that occurred on September 27, 2008, STS-125 was delayed until now to prepare a second data handling unit replacement for the telescope. Over 11 days and five spacewalks (EVA’s), the shuttle Atlantis’ crew will enhance the observatory and ensure its cutting-edge science by putting in place advanced technology that improves its discovery power by 10 to 70 times. Unfortunately, I wasn’t able to follow this launch as closely as the launch of Discovery in March.

Discovery on pad 39A minutes before launch - Source: NASA TV

Discovery on pad 39A minutes before launch - Source: NASA TV

Countdown clock at 30:49 - 10:49 before the T-20 built-in hold - Source: NASA TV

Atlantis takes off in HD – Courtery of NASA TV Youtube Channel:

A few minutes after the liftoff, the crew executed a Orbiter Maneuvering System (OMS) burn to raise the shuttle’s orbit to reach Hubble’s 563-8km above the surface. The shuttle it now on its way to rendezvous with the space telescope on Wednesday.  During the mission, the STS-125 crew aboard Atlantis will travel farther from the Earth than anyone since STS-109 in March 2002, which flew on Space Shuttle Columbia. The mission is scheduled to end on Friday, May 22, 2009 at 15:41 UT when the shuttle is supposed to land at the Shuttle Landing Facility at Kennedy’s Space Center in Florida.

Follow the mission on NASA TV and don’t forget to subscribe to Astro_Mike‘s tweeps from space!