Russia's Cosmos 2495: Fiery Fall of Russian Spy Satellite Debris

A global network of skywatching detectives has pieced together the strange story of a Russian military spy satellite that re-entered Earth's atmosphere earlier this month, the leftovers of which sparked a spectacular sky show over five U.S. states.

Observers across parts of Montana, South Dakota, Wyoming, Colorado and New Mexico caught sight of debris from the military satellite via a fireball on Sept. 2 around 10:30 p.m. Mountain Daylight Time, reporting their observations to the American Meteor Society.

The focus of attention is Russia's Cosmos 2495, an Earth-imaging reconnaissance (Kobalt-M) satellite. It was a hefty spacecraft, in the Kobalt-M series, a family member of the Yantar chain of Russian satellites. Russia launched the satellite on its intelligence-gathering mission on May 6 of this year. [Photos: Declassified U.S. Spy Satellites]

The resulting fireball from parts of the Cosmos 2495 spysat's re-entry was not only spotted by skywatchers. It was also caught that night by a number of all-sky cameras, including the Cloudbait Observatory  here in the central Colorado Rocky Mountains.

An on-line buzz about the occurrence found a home at SeeSat-L, the mailing list for visual satellite observers, which has become an invaluable tool to study all manner of spacecraft events. So here's what happened with Cosmos 2495.

Satellite tracker Thomas Ashcraft, of Heliotown in Santa Fe, New Mexico, captured this long-exposure view of the brilliant fireball created by debris from a suspected Russian spy satellite on Sept. 2, 2014. 

Credit: Thomas Ashcraft/Heliotown

Graphic shows the actual time and track of the suspected piece of Russian Cosmos 2495 debris in relation to sightings.

Credit: Ted Molczan

Russian spysat falls from space

This multipart Cosmos 2495 consists of an equipment module, an instrument module, a camera re-entry vehicle and a large sun shade with additional antennae and sensors.

It is designed to re-enter Earth's atmosphere so that its camera canister can be retrieved by a recovery crew.

At the end of its mission on Sept. 2, the Russian spysat fired its engine to begin its return to Earth. Its fiery re-entry was witnessed and videoed from a large part of western Kazakhstan.

The module carrying the cargo of exposed film and a reusable camera separated, and is believed to have landed near the city of Orenburg in Russia. The remainder of the spacecraft, meanwhile, burned up as planned.

Now, it appears that the slow-moving fireball spotted over the U.S. on Sept. 2 — some 10 hours after Cosmos 2495's intelligence camera module had safely touched down — was due to a lingering leftover from the Soviet military spacecraft.

CSIRO Astronomers spy on galaxies in the raw

Antennas of CSIRO's Compact Array telescope. Photo: David Smyth

A CSIRO radio telescope has detected the raw material for making the first stars in galaxies that formed when the Universe was just three billion years old—less than a quarter of its current age.

This opens the way to studying how these early galaxies make their first stars.

The telescope is CSIRO's Australia Telescope Compact Array telescope near Narrabri, NSW.

"It one of very few telescopes in the world that can do such difficult work, because it is both extremely sensitive and can receive radio waves of the right wavelengths," says CSIRO astronomer Professor Ron Ekers.

The raw material for making stars is cold molecular hydrogen gas, H2. It can't be detected directly but its presence is revealed by a 'tracer' gas, carbon monoxide (CO), which emits radio waves.

In one project, astronomer Dr Bjorn Emonts (CSIRO Astronomy and Space Science) and his colleagues used the Compact Array to study a massive, distant conglomerate of star-forming 'clumps' or 'proto-galaxies' that are in the process of coming together as a single massive galaxy.

This structure, called the Spiderweb, lies more than ten thousand million light-years away [at a redshift of 2.16].

Dr Emonts' team found that the Spiderweb contains at least sixty thousand million [6 x 1010] times the mass of the Sun in molecular hydrogen gas, spread over a distance of almost a quarter of a million light-years.

This must be the fuel for the star-formation that has been seen across the Spiderweb. "Indeed, it is enough to keep stars forming for at least another 40 million years," says Emonts.

In a second set of studies, Dr Manuel Aravena (European Southern Observatory) and colleagues measured CO, and therefore H2, in two very distant galaxies [at a redshift of 2.7].

The faint radio waves from these galaxies were amplified by the gravitational fields of other galaxies—ones that lie between us and the distant galaxies. This process, called gravitational lensing, "acts like a magnifying lens and allows us to see even more distant objects than the Spiderweb," says Dr Aravena.

More information: Emonts BHC and 15 co-authors. CO(1-0) detection of molecular gas in the massive Spiderweb Galaxy (z=2). Monthly Notices of the Royal Astronomical Society 430, 3465 (2013). Online at arxiv.org/abs/1301.6012

Aravena M and 28 co-authors. Large gas reservoirs and free-free emission in two lensed star-forming galaxies at z = 2.7. Accepted for publication in Monthly Notices of the Royal Astronomical Society. Online at arxiv.org/abs/1305.0614