Hartebeesthoek Radio Astronomy Observatory
Encyclopedia
The Hartebeesthoek Radio Astronomy Observatory (HartRAO) is a radio astronomy
observatory
located in a natural bowl of hills at Hartebeesthoek just south of the Magaliesberg
mountain range, Gauteng
, South Africa
, about 50 km west of Johannesburg
. It is a National Research Facility run by South Africa's National Research Foundation
and is the only major radio astronomy observatory in Africa
.
space missions, including the Ranger, Surveyor and Lunar Orbiter spacecraft (which landed on the Moon
or mapped it from orbit), the Mariner missions (which explored the planets Venus
and Mars
) and the Pioneer missions (which measured the Sun
's winds).
NASA withdrew from the station in 1975, handing it over to South Africa's Council for Scientific and Industrial Research
(CSIR), who converted it to a radio astronomy observatory. In 1988 the observatory became a National Facility operated by the Foundation for Research Development (FRD); in 1999 the FRD was restructured as the National Research Foundation
(NRF).
, NASA continues to contract for launch tracking services on an as-needed basis, and did so for the launch of the Mars Science Laboratory
on 26 November 2011.
radio telescope
with a main reflecting surface diameter
of 26 metres. The telescope is equipped with radio
receivers operating in the microwave
band at wavelengths of 18cm, 13cm, 6cm, 4.5cm, 3.5cm, 2.5cm and 1.3cm.
HartRAO is mainly used for continuum radiometry
, spectroscopy
, pulsar
timing and interferometry
but also works together with radio telescopes on other continents as well as the orbiting radio telescope HALCA
in order to perform Very Long Baseline Interferometry
(VLBI).
HartRAO is an associate member of the European VLBI Network
, but also operates with the Australia Telescope Long Baseline Array, the Asia-Pacific Telescope, the United States Very Long Baseline Array
and the Global Array.
HartRAO also runs a Space Geodesy programme using VLBI, Satellite laser ranging
and the Global Positioning System
.
The observatory also provides students and lecturers from South African universities the facilities and opportunities to perform research.
radio telescope, has been constructed at HartRAO. The XDM dish design will first be used in KAT-7, a seven-dish engineering testbed and science instrument to be built in Carnarvon
in the Northern Cape Province. KAT-7 will mark the first stage of MeerKAT development. MeerKAT, a 50+ dish system, will be built on the same site, and is projected to be operational by 2012.
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
observatory
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...
located in a natural bowl of hills at Hartebeesthoek just south of the Magaliesberg
Magaliesberg
The Magaliesberg is a mountain range extending from Pretoria in the north of the Gauteng Province to a point south of Pilanesberg, in the North West Province, South Africa...
mountain range, Gauteng
Gauteng
Gauteng is one of the nine provinces of South Africa. It was formed from part of the old Transvaal Province after South Africa's first all-race elections on 27 April 1994...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, about 50 km west of Johannesburg
Johannesburg
Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...
. It is a National Research Facility run by South Africa's National Research Foundation
National Research Foundation of South Africa
South Africa’s National Research Foundation is the intermediary agency between the policies and strategies of the Government of South Africa and South Africa's research institutions....
and is the only major radio astronomy observatory in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
.
History
The observatory was originally named Deep Space Station 51 and was built in 1961 by the National Aeronautics and Space Administration (NASA). In this role the station assisted in tracking many unmanned United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
space missions, including the Ranger, Surveyor and Lunar Orbiter spacecraft (which landed on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
or mapped it from orbit), the Mariner missions (which explored the planets Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
and Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
) and the Pioneer missions (which measured the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
's winds).
NASA withdrew from the station in 1975, handing it over to South Africa's Council for Scientific and Industrial Research
Council for Scientific and Industrial Research
The Council for Scientific and Industrial Research is South Africa's central and premier scientific research and development organisation. It was established by an act of parliament in 1945 and is situated on its own campus in the city of Pretoria...
(CSIR), who converted it to a radio astronomy observatory. In 1988 the observatory became a National Facility operated by the Foundation for Research Development (FRD); in 1999 the FRD was restructured as the National Research Foundation
National Research Foundation of South Africa
South Africa’s National Research Foundation is the intermediary agency between the policies and strategies of the Government of South Africa and South Africa's research institutions....
(NRF).
, NASA continues to contract for launch tracking services on an as-needed basis, and did so for the launch of the Mars Science Laboratory
Mars Science Laboratory
The Mars Science Laboratory is a National Aeronautics and Space Administration mission with the aim to land and operate a rover named Curiosity on the surface of Mars. The MSL was launched November 26, 2011, at 10:02 EST and is scheduled to land on Mars at Gale Crater between August 6 and 20, 2012...
on 26 November 2011.
The Radio Telescope
The observatory is equipped with a single 260 tonTon
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...
radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
with a main reflecting surface diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
of 26 metres. The telescope is equipped with radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
receivers operating in the microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
band at wavelengths of 18cm, 13cm, 6cm, 4.5cm, 3.5cm, 2.5cm and 1.3cm.
Research
Radiometry
In optics, radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye...
, spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
, pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...
timing and interferometry
Interferometry
Interferometry refers to a family of techniques in which electromagnetic waves are superimposed in order to extract information about the waves. An instrument used to interfere waves is called an interferometer. Interferometry is an important investigative technique in the fields of astronomy,...
but also works together with radio telescopes on other continents as well as the orbiting radio telescope HALCA
HALCA
The HALCA , also known for its project name VSOP , or the code name MUSES-B for the second of the Mu Space Engineering Spacecraft series, is a Japanese 8 meter diameter radio telescope satellite which was used for Very Long Baseline Interferometry...
in order to perform Very Long Baseline Interferometry
Very Long Baseline Interferometry
Very Long Baseline Interferometry is a type of astronomical interferometry used in radio astronomy. It allows observations of an object that are made simultaneously by many telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.Data...
(VLBI).
HartRAO is an associate member of the European VLBI Network
European VLBI Network
The European VLBI Network was formed in 1980 by a consortium of five of the major radio astronomy institutes in Europe . Since 1980, the EVN and the Consortium has grown to include 9 institutes with 12 radio telescopes in 8 western European countries as well as associated institutes with...
, but also operates with the Australia Telescope Long Baseline Array, the Asia-Pacific Telescope, the United States Very Long Baseline Array
Very Long Baseline Array
The Very Long Baseline Array is a system of ten radio telescopes controlled remotely from the Array Operations Center in Socorro, New Mexico by the National Radio Astronomy Observatory. The array works together as the world's largest dedicated, full-time astronomical instrument using the...
and the Global Array.
HartRAO also runs a Space Geodesy programme using VLBI, Satellite laser ranging
Satellite laser ranging
In satellite laser ranging a global network of observation stations measure the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors...
and the Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
.
The observatory also provides students and lecturers from South African universities the facilities and opportunities to perform research.
Involvement with the Karoo Array Telescope Project
The XDM, a prototype dish for the MeerKATMeerKAT
MeerKAT is a radio telescope under construction in the Northern Cape of South Africa. It will be the largest and most sensitive radio telescope in the southern hemisphere until the Square Kilometer Array is completed around 2024.The telescope will be used for research into cosmic magnetism,...
radio telescope, has been constructed at HartRAO. The XDM dish design will first be used in KAT-7, a seven-dish engineering testbed and science instrument to be built in Carnarvon
Carnarvon, South Africa
Carnarvon is a small town in the Northern Cape Province of South Africa. Originally established in 1860 as the village of Harmsfontein, it was located within the territory of Schietfontein, the only water source in the area and the site of the Rhenish mission station founded in 1847 by the...
in the Northern Cape Province. KAT-7 will mark the first stage of MeerKAT development. MeerKAT, a 50+ dish system, will be built on the same site, and is projected to be operational by 2012.
See also
- National Research Foundation of South AfricaNational Research Foundation of South AfricaSouth Africa’s National Research Foundation is the intermediary agency between the policies and strategies of the Government of South Africa and South Africa's research institutions....
- South African Astronomical ObservatorySouth African Astronomical ObservatorySouth African Astronomical Observatory is the national center for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's function is to conduct research in astronomy and astrophysics...
- Deep Space NetworkDeep Space NetworkThe Deep Space Network, or DSN, is a world-wide network of large antennas and communication facilities that supports interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the solar system and the universe, and supports selected...