Why in News?

• The Atacama Large Millimetre/submillimetre Array (ALMA) is set to get software and hardware upgrades that will help it collect much more data and produce sharper images than ever before.
• As ALMA is operated under a partnership among the US, 16 countries in Europe, Canada, Japan, South Korea, Taiwan and Chile, the announcement came after all the partners cleared the funding required for the improvements.

What’s in Today’s Article?

• What is ALMA?
• What is Submillimetre Astronomy?
• Why is ALMA Located in Chile’s Atacama Desert?
• What are Some of the Notable Discoveries made by ALMA?

What is ALMA?

• ALMA is a state-of-the-art radio-telescope that studies celestial objects at millimetre and submillimetre wavelengths that can penetrate through dust clouds and help astronomers examine dim and distant galaxies and stars.
• Fully functional since 2013, it was designed, planned and constructed by the US’s National Radio Astronomy Observatory (NRAO), the National Astronomical Observatory of Japan (NAOJ) and the European Southern Observatory (ESO).
• It also has extraordinary sensitivity, which allows it to detect even extremely faint radio signals.
• It consists of 66 high-precision antennas, spread over a distance of up to 16 km in the Atacama Desert of northern Chile.
• These antennas can be moved closer together or farther apart for different perspectives - like the zoom lens of a camera.

 What is Submillimetre Astronomy?

• Light at these wavelengths comes from vast cold clouds in interstellar space (at temperatures little above absolute zero) and from some of the earliest and most distant galaxies in the Universe.
• Astronomers can use it to study the chemical and physical conditions in molecular clouds - the dense regions of gas and dust where new stars are being born.
• Often these regions of the Universe are dark and obscured in visible light, but they shine brightly in the millimetre and submillimetre part of the spectrum.

 Why is ALMA Located in Chile’s Atacama Desert?

• ALMA is situated at an altitude of 16,570 feet (5,050 m) above sea level on the Chajnantor plateau in Chile’s Atacama Desert.
• The desert is the driest place in the world, meaning most of the nights here are clear of clouds and free of light-distorting moisture.
• All these make it a perfect location for examining the universe, as the millimetre and submillimetre waves observed by it are very susceptible to atmospheric water vapour absorption on Earth.

 What are Some of the Notable Discoveries made by ALMA?

• Scientists are trying to find answers to age-old questions of our cosmic origins.
• One of the earliest findings came in 2013 when it discovered starburst galaxies and the dust formation inside supernova 1987A.
• Next year, ALMA provided detailed images of the protoplanetary disc surrounding HL Tauri - a very young T Tauri star in the constellation Taurus, approximately 450 light years from Earth.
• In 2015, the telescope helped scientists observe a phenomenon known as the Einstein ring, which occurs when light from a galaxy or star passes by a massive object en route to the Earth.
• More recently, as part of the Event Horizon Telescope project - a global network of radio telescopes, it provided the first image of the supermassive black hole at the centre of our own Milky Way galaxy.