5 Radio Telescope Discoveries That Are Significant In AstronomySince radio telescopes were developed, significant discoveries have been made. Here we list 5 amazing radio telescope discoveries.
What is Radio Astronomy?
Radio telescopes enable astronomers to look at radio waves from space. It works similarly to optical telescopes, however as an alternative to visible light, radio waves are collected and reflected. Radio waves and microwaves have longer wavelengths than visible light, which astronomers use to collect information similar to the frequency, power, and timing of radio emissions from objects. In turn, this allows them to infer details about space that isn't achievable with traditional telescopes.
The biggest radio telescope on the planet is the Arecibo telescope in Arecibo, Puerto Rico. Though radio telescopes had been used since the 1930s, Arecibo was instrumental in astronomical discoveries since 1960. Developed and operated by Cornell University, radio telescopes are now valuable tools for observing objects that we're not able to see with optical telescopes.
Since radio telescopes were developed, many important discoveries have been made. Here we list 5 amazing radio telescope discoveries which changed the way we view the universe.
Asteroid Imaging with Radio Telescopes
In 1989, the Arecibo telescope picked up an asteroid referred to as 4769 Castalia. Asteroids have been discovered long before radio telescopes, however, this has been the first time scientists used technology to create a picture of what the asteroid looked like. Thanks to radar imaging, Scott Hudson and Steven Ostro were able to develop a 3-dimensional model of the peanut-shaped Castalia.
Modern telescopes can achieve a much higher resolution, producing more detailed images. Two or more telescopes can also be paired for even greater resolution. Using one telescope to transmit and another to receive can yield significantly more detail than one telescope, and it is a useful method to obtain radar pictures of closely approaching, slowly rotating asteroids.
Binary Pulsar and Millisecond Pulsar Discovery
In 1993, Russell Hulse and Joseph Taylor's won the Nobel Prize in Physics for their discovery of pulsars using radio telescopes in 1974. A binary pulsar is a pulsar that has a white dwarf or neutron star close by that orbits the pulsar to balance the mass and gravitational direction of the pulsar. Millisecond pulsars are neutron stars with an excessively fast rotational duration.
Astronomers are using pulsars all through the Milky Way Galaxy as an enormous scientific instrument to directly discover gravitational waves that have been predicted by Einstein's general theory of relativity.
Exoplanets Discovered with Radio Telescopes
On January 9, 1992, astronomers Alex Wolszczan and Dale Frail came upon exoplanets which are orbiting a pulsar named PSR 1257+12. Like many of the discoveries on this list, it took place at the Arecibo Observatory in Puerto Rico.
Exoplanets are planets that exist outside our Sun's solar system. The discovered exoplanets are about 4 times as large as our planet, and their proportions closely resemble the spacing between Mercury, Venus, and Earth.
These planets are believed to be orbiting the aforementioned pulsar positioned about 2,300 light-years away within the constellation Virgo. The innermost one circles it every 67 days, while the outer one circles every 98 days. There's additionally a conceivable third planet which is further from the pulsar and orbits it about every 360 days.
Mercury's Orbit Discovered with Radio Telescope Observations
Using the Arecibo telescope, Gordon Pettengill developed a theory about the rotation of Mercury. In 1964, Pettengill used the radio telescope to theorize that the real rotation of the planet was 59 days. It had been in the past thought that Mercury's orbit takes 88 Earth days, however, this discovery opened new research on the planet and it was revealed that Mercury rotates 3 times for every two revolutions around the Sun.
21 CM Hydrogen Line
The 21 CM Hydrogen Line was discovered and observed by Edward Purcell & Harold Ewen in 1951 and since then radio astronomers have been mapping neutral hydrogen within the galaxy. This is helping astronomers map the hydrogen within the galaxy, which ultimately leads to the publishing of the spiral structure of the Milky Way.
Assuming that the hydrogen atoms are uniformly distributed all over the galaxy, each line of sight through a galaxy will reveal a hydrogen line. The only distinction between each of these lines is the Doppler shift that each of these lines has. Hence, one can calculate the relative velocity of each arm of our galaxy. The rotation curve of our galaxy has been calculated using the 21 cm hydrogen line. It is then possible to make use of the plot of the rotation curve and the velocity to determine the distance to a certain point inside the galaxy.
