Cameras for All-Sky Meteor Surveillance

Lore & Background

CAMS networks around the world use low-light video surveillance cameras to collect astrometric tracks and brightness profiles of meteors. Triangulation of those tracks yields the meteor's direction and speed, from which its orbit in space is calculated and the parent body can be identified. The software modules, written by Peter S. Gural, have scaled up video-based triangulation, with scripts to run them on PCs written by Dave Samuels and Steve Rau. Each streak of light is identified and verified as a meteor or other light source through computational and statistical algorithms.

The first CAMS camera stations were set up in October 2010 at Fremont Peak Observatory and in Mountain View, followed in April 2011 by a station at Lick Observatory, all in California. A station in Foresthill was added in April 2015. CAMS has since expanded into 15 networks worldwide, including locations in the USA (California, Northern California, Arizona, Texas, Arkansas, Maryland, and Florida), the BeNeLux, the United Arab Emirates, and on the southern hemisphere in New Zealand, Australia, South Africa, Namibia, Brazil, and Chile.

Notable contributions include demonstrating the presence of yet-to-be-discovered long-period comets and improving their orbits. In April 2021, CAMS identified 14 to 20 known long-period comets as parent bodies of meteor showers. The project also discovered new showers, such as the February Eta Draconids on February 4, 2011, proving the existence of a still-undiscovered long-period comet. CAMS has also guided astronomers in locating freshly fallen meteorites, including the Novato meteorite in 2012 and a -20 magnitude fireball in 2016 from which 15 meteorites were recovered.

Reader's Guide

CAMS is significant for its systematic validation and expansion of the International Astronomical Union's Working List of Meteor Showers. As of February 17, 2021, it helped establish 92 out of 112 single showers and recognized 323 out of 700 meteor showers in the Working List. The project has discovered new showers, such as the February Eta Draconids, gamma Piscis Austrinids, and the Arids from comet 15P/Finlay, and has verified previously radar-only showers like the rho Phoenicids and April Rho Cygnids. CAMS also monitors unusual activity, detecting outbursts from comets like 15P/Finlay, 109P/Swift-Tuttle, and 8P/Tuttle, and has captured record numbers of meteors in a single night, such as 3003 Geminids on December 13, 2017. Its data guides astronomers in locating meteorite falls, as demonstrated with the Novato meteorite and a fireball that yielded LL type chondrites. The project's online portal at cams.seti.org/FDL/ provides nightly maps of meteor shower activity for scientists and amateur astronomers.

Did You Know?

• CAMS detected a brief meteor shower from a still-undiscovered long-period comet on February 4, 2011, proving the comet's existence.
• On December 13, 2017, CAMS captured 3003 Geminids and 1154 sporadic meteors, shattering all previous records for a single night.
• CAMS detected the first meteors from comet 15P/Finlay in September 2021, naming the new shower the Arids.
• The Novato meteorite was retrieved by a local resident after CAMS published tracking information in 2012.

The Physics of a Near-Earth Impact

The Chelyabinsk superbolide arrived on the morning of 15 February 2013 as a roughly 18-metre, 9,100-tonne near-Earth asteroid plunging into the atmosphere over the southern Urals. Its trajectory was notably shallow—just 18 degrees from horizontal—and its velocity relative to Earth reached approximately 19.2 kilometres per second, a speed that carried it at nearly sixty times the speed of sound. As it tore through the upper atmosphere, the object's total kinetic energy was on the order of 400 to 500 kilotonnes of TNT, a figure derived from infrasound and seismic readings. That placed the blast roughly thirty times the yield of the Hiroshima atomic bomb. Most of that energy was deposited into the surrounding air rather than the ground, generating a massive shock wave and a hot cloud of dust and gas that descended to around 26 kilometres altitude. The initial air burst occurred at roughly 30 kilometres above Chelyabinsk Oblast, and the surviving fragments then entered a phase of dark flight before scattering across the snow-covered terrain as officially designated Chelyabinsk meteorites.

The Shock Wave and Its Human Toll

No one was killed by the Chelyabinsk event, yet nearly 1,500 people required medical attention in the hours that followed. Every recorded injury stemmed from indirect effects—overwhelmingly from shattered window glass that the arriving shock wave hurled through homes and offices minutes after the initial flash. The blast wave was powerful enough to damage approximately 7,200 buildings spread across six cities in the region, and repair crews worked in sub-freezing winter conditions to make structures safe. Witnesses in Chelyabinsk described the air as carrying smells of gunpowder, sulfur, and burning material for the rest of the day. Some observers in the wider area reported feeling intense radiant heat from the fireball, and a small number experienced skin or retinal burns. The shock wave arrived well after the visual event, meaning people who had looked up at the sky were caught off guard when their windows exploded inward. The event was witnessed across Chelyabinsk, Kurgan, Sverdlovsk, Tyumen, and Orenburg Oblasts, as well as the Republic of Bashkortostan and parts of neighbouring Kazakhstan.

Caught on Camera and in the Sky

The Chelyabinsk meteor approached Earth without prior detection, a fact complicated by its radiant—the apparent direction from which it seemed to originate—sitting close to the rising Sun. Despite this, the event was captured by multiple independent sources. The weather satellite Meteosat 9 recorded an image of the object shortly after atmospheric entry. On the ground, amateur videos, dashcam recordings, and CCTV footage from across the region documented the fireball streaking overhead and the delayed thunderous boom. NASA later confirmed that at peak brightness, reached at 09:20:33 local time, the object was brighter than the Sun itself, a magnitude of roughly −26.7, and visible from as far as 100 kilometres away. Early dashcam analysis suggested the meteor came from the southeast and detonated about 40 kilometres south of central Chelyabinsk above Korkino. A more rigorous calibration study conducted by the Russian Academy of Sciences in November 2013 refined the peak-brightness altitude to approximately 29.7 kilometres, with the thermal debris cloud ultimately settling near 26.2 kilometres.

A Place in the Record Books

The Chelyabinsk superbolide stands as the largest confirmed natural space object to enter Earth's atmosphere since the 1908 Tunguska event, which obliterated a vast, remote stretch of Siberian forest. Unlike Tunguska, however, the Chelyabinsk impact occurred over a densely populated urban area, making it the only comparable event in the record confirmed to have caused numerous human injuries. A small number of panic-related injuries were noted during the Great Madrid Meteor Event of 10 February 1896, but no other modern analogue exists. In the Chelyabinsk region specifically, the previous notable meteor phenomenon was the Kunashak meteor shower of 1949, which yielded roughly 20 recovered stones totalling over 200 kilograms. Adding to the day's astronomical significance, a much larger asteroid—367943 Duende, approximately 30 metres across—made a well-publicized close approach to Earth about 16 hours after the Chelyabinsk flash. Orbital analysis confirmed the two objects followed entirely different paths and were unrelated, making the coincidence purely a matter of timing.