Author: Astronomy & Astrophysics

Comet McNaught next to the dome of the NTT on …

Comet McNaught next to the dome of the NTT on La Silla. The picture was taken in January 2007.

Credit: ESO/H.H.Heyer

Vortex at Saturn’s North Pole Credi…

Vortex at Saturn’s North Pole

Credit: NASA/JPL-Caltech/Space Science Institute

astronomyblog: The veil nebula is 110 light-y…


The veil nebula is 110 light-years across, covering six full moons in the sky, seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus the Swan.

Image credit: NASA, ESA & Hubble

astronomyblog: 67P/Churyumov-Gerasimenko …



67P/Churyumov–Gerasimenko (abbreviated as 67P or 67P/C-G) is a Jupiterfamily comet, originally from the Kuiper belt, with a current orbital period of 6.45 years, a rotation period of approximately 12.4 hours and a maximum velocity of 135,000 km/h (38 km/s; 84,000 mph) Churyumov–Gerasimenko is approximately 4.3 by 4.1 km (2.7 by 2.5 mi) at its longest and widest dimensions. It was first observed on photographic plates in 1969 by Soviet astronomers Klim Ivanovych Churyumov and Svetlana Ivanovna Gerasimenko, after whom it is named. It came to perihelion (closest approach to the Sun) on 13 August 2015.

67P and the Rosetta Mission


Churyumov–Gerasimenko was the destination of the European Space Agency’s Rosetta mission, launched on 2 March 2004. Rosetta rendezvoused with Churyumov–Gerasimenko on 6 August 2014 and entered orbit on 10 September 2014. Rosetta’s lander, Philae, landed on the comet’s surface on 12 November 2014, becoming the first spacecraft to land on a comet nucleus. On 30 September 2016, the Rosetta spacecraft ended its mission by landing on the comet in its Ma’at regio.

astronomyblog: Time-lapse sequence from the…


Time-lapse sequence from the approach of Voyager 1, showing the motion of atmospheric bands and circulation of the Great Red Spot.

Credit: NASA/JPL

astronomyblog: This enhanced-color image of J…


This enhanced-color image of Jupiter’s bands of light and dark clouds was created by citizen scientists Gerald Eichstädt and Seán Doran using data from the JunoCam imager on NASA’s Juno spacecraft.

Three of the white oval storms known as the “String of Pearls” are visible near the top of the image. Each of the alternating light and dark atmospheric bands in this image is wider than Earth, and each rages around Jupiter at hundreds of miles (kilometers) per hour. The lighter areas are regions where gas is rising, and the darker bands are regions where gas is sinking.

Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt /Seán Doran

astronomyblog: In this image, Space Shuttle C…


In this image, Space Shuttle Challenger waits on Launch Complex 39A at Kennedy Space Center before its first mission, STS-6, launched on April 4, 1983. Originally built as a test vehicle, in 1979 NASA issued a contract to convert it to a fully space-rated orbiter. It became the second operational Shuttle, delivered to Kennedy Space Center in July 1982. Challenger was destroyed shortly after lift off on her 10th mission, STS-51L, on January 28, 1986.

Image credit: NASA

astronomyblog: What is the Atacama Large Mill…


What is the Atacama Large Millimeter/submillimeter Array (ALMA)?

High on the Chajnantor plateau in the Chilean Andes, the European Southern Observatory (ESO), together with its international partners, is operating the Atacama Large Millimeter/submillimeter Array (ALMA) — a state-of-the-art telescope to study light from some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves, and is therefore known as millimetre and submillimetre radiation. ALMA comprises 66 high-precision antennas, spread over distances of up to 16 kilometres. This global collaboration is the largest ground-based astronomical project in existence.

The antennas can be moved across the desert plateau over distances from 150 m to 16 km, which will give ALMA a powerful variable “zoom”, similar in its concept to that employed at the Very Large Array (VLA) site in New Mexico, United States.

What is submillimetre astronomy?

Light at these wavelengths comes from vast cold clouds in interstellar space, at temperatures only a few tens of degrees 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 build ALMA in the high Andes?

Millimetre and submillimetre radiation opens a window into the enigmatic cold Universe, but the signals from space are heavily absorbed by water vapour in the Earth’s atmosphere. Telescopes for this kind of astronomy must be built on high, dry sites, such as the 5000-m high plateau at Chajnantor, one of the highest astronomical observatory sites on Earth.

The ALMA site, some 50 km east of San Pedro de Atacama in northern Chile, is in one of the driest places on Earth. Astronomers find unsurpassed conditions for observing, but they must operate a frontier observatory under very difficult conditions. Chajnantor is more than 750 m higher than the observatories on Mauna Kea, and 2400 m higher than the VLT on Cerro Paranal.


astronomyblog: Illustrations and records of c…


Illustrations and records of comets, planets, constellations and nebulae.

Internet Archive Book Images

Titan: Ligeia Mare and environs Numerous lake…

Titan: Ligeia Mare and environs

Numerous lakes of hydrocarbons and seas are visible: at the top is the prominent body of liquid known as Ligeia Mare; the main centers are in the northernmost part of Kraken Mare and on the island of Mayda Insula; and in the bottom center is a portion of Punga Mare. In the lower right corner, Jingpo Lacus reveals a series of sinuous canals in its lake bed, while Bolsena Lacus appears in the lower left corner.

Credit: NASA/JPL-Caltech/Space Science Institute/Ian Regan