Late day at the Uppsala Schmidt Telescope at Siding Spring Observatory, New South Wales, Australia. The telescope is used for the Siding Spring Survey, the southern hemisphere counterpart to UAs Catalina Sky Survey. Both projects search for Earth-approaching asteroids. (Photo: Courtesy of Steve Larson, Catalina Sky Survey)
The hunt for space rocks on a collision course with Earth has so far been pretty much limited to the Northern Hemisphere.
But last week astronomers took the search for Earth-threatening asteroids to southern skies.
Astronomers using a refurbished telescope at the Australian National Universitys Siding Spring Observatory discovered their first two near-Earth asteroids (NEAs) on March 29. NEAs are asteroids that pass near the Earth and may pose a threat of collision.
Siding Spring Survey (SSS) astronomer Gordon Garradd detected a roughly 100-meter (about 300-foot) diameter asteroid and 300-meter (about 1,000-foot) diameter asteroid in images he obtained with the 0.5-meter (20-inch) Uppsala Schmidt telescope.
SSS partner Robert H. McNaught confirmed both discoveries in images he took with the Siding Spring 1-meter (40-inch) that same night.
The 100-meter asteroid, designated 2004 FH29, makes a complete orbit around the sun every 2.13 years. It missed Earth by 3 million kilometers (1.9 million miles), or 8 times the Earth-to-moon distance, yesterday, traveling at 10 km per second (22,000 mph) relative to Earth.
The 300-meter asteroid, designated 2004 FJ29, orbits the sun about every 46 weeks. It came within 20 million kilometers (12 million miles), or within 52 lunar distances of Earth, last Tuesday, March 30, traveling at 18 km per second (40,000 mph) relative to Earth.
Neither object poses a direct threat of colliding with Earth.
Had the asteroids not missed, damage from their impacts would have depended on what kind of rock theyre made of. The 100-meter object likely would mostly burn up in Earths atmosphere in an airblast equivalent to 10 megatons of TNT, comparable to the 1908 explosion above the Tunguska River valley in Siberia, McNaught said. The 300-meter rocky asteroid likely would reach Earths surface, dumping the equivalent of 1,400 megatons of TNT energy into Earths atmosphere, he added. Thats comparable to 200 Tunguskas, or 24 times the largest thermonuclear bomb explosion, a 58 megaton Soviet bomb exploded in 1961.
The new survey is a joint collaboration between the University of Arizona Lunar and Planetary Laboratory and ANUs Research School of Astronomy and Astrophysics. It is funded by NASAs Near-Earth Object Observation Program, a 10-year effort to discover and track at least 90 percent of the one kilometer (six-tenths of a mile) or larger NEOs with the potential to become impact hazards.
When astronomers detect what they suspect is an NEA, they immediately must take additional images to confirm their discovery, McNaught said. Surveys often have to suspend their NEA searches and spend observing time confirming NEAs, or they risk losing them altogether because follow-up observations were made too late, he added.
The SSS plan is to use the 1-meter (40-inch) telescope for part of the month to quickly confirm suspect asteroids detected with the Uppsala, freeing the smaller telescope to continue it searches.
"Our confirmation strategy worked beautifully on our first try," McNaught said.
The Uppsala Schmidt telescope was built in the 1950s for Uppsala Observatory in Sweden. It was sited at Stromlo as the Uppsala Southern Station to make wide field photographs of the southern sky. Increasing light pollution from Canberra led to its relocation to Siding Spring, near Coonabarabran in New South Wales, in the late 1982. Despite its high quality optics, the telescope drifted into disuse because it used photographic film rather than modern electronic detectors and had to be operated manually.
In 1999, McNaught and Stephen M. Larson of UA¹s Lunar and Planetary Laboratory joined in an effort to refurbish and upgrade the Uppsala telescope. Larson had similarly just overhauled a manually operated, photographic wide-field Schmidt telescope in the Santa Catalina Mountains north of Tucson for his Catalina Sky Survey (CSS), part of the NASA-funded program to spot and track asteroids headed toward Earth.
The SSS builds on telescope control, detector technology and software developed for the CSS in Tucson. During the upgrade, the Uppsala was completely reconditioned, and fitted with computer control, a large format (16 megapixel) solid state detector array, and extensive support computers and software that detects objects moving against background stars.
Larson said his reaction to the SSS milestone was "one of relief, since it took several years to make the telescope and facility modifications. Now the real work begins."
Larson and Catalina Sky Survey team member Ed Beshore worked on commissioning the Uppsala telescope during the past few months. Commissioning a telescope is like commissioning a ship: You have to get all the parts working and working together, and adjust things so they perform as expected.
"We actually achieved first light last summer, with good images from the start," Larson said.
McNaught and Garradd will operate SSS about 20 nights each month. They suspend operations when the week around full moon brightens the sky, making faint object detection difficult.
The Catalina telescope, which Larson and his team upgraded again in May 2000, features new optics that give it a 69 centimeter (27-inch) aperture and a new, more sensitive camera. In addition to Larson and Beshore, Eric Christensen, Rik Hill, David McLean, and Serena Howard operate CSS.
Both CSS and SSS telescopes can detect objects as faint as 20th magnitude, close to sky background level generated by scattered city light and auroral glow that brightens Earth¹s upper atmosphere.
Lori Stiles | University of Arizona
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy