A Day in Astronomy: The Founding of the European Space Agency

On this day in 1975, the European Space Agency (ESA) was founded after the combination of  the European Space Research Organisation (ESRO) and the European Launcher Development Organisation (ELDO). Ten countries were part of this new organization, which has since grown to 22 members (noted below). The Agency also has associate members and other cooperating partners.

You can find a list of the ESA’a past, present, and planned space missions here, which includes:

Note: According to the International Astronautical Federation, the ESA member include Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland and the United Kingdom. Latvia, Lithuania and Slovenia are Associate Members. Canada takes part in certain programmes under a cooperation agreement. ESA has signed European Cooperating States Agreements with Bulgaria, Cyprus and Slovakia, and cooperation agreements with Croatia and Malta.

A Day in Astronomy: The Hubble Space Telescope is Launched

Image (Credit): The Hubble Space Telescope orbits with Earth in the background. (NASA)

On this day in 1990, NASA’s Space Shuttle Discovery launched the Hubble Space Telescope. We do not think of the shuttles anymore as we discuss reusable rockets, but the shuttles were the first reusable spacecraft-launching vehicles.

After some initial problems, the Hubble became a critical component in the exploration of the universe. Some of the telescope’s amazing images are shown below.

It is still going strong, even though its successor, the James Webb Space Telescope (JWST), is the more powerful of the two. Launched in late 2021, the JWST has expanded on some of Hubble’s earlier work. The pair are a powerful team.

Here are a few interesting facts about Hubble:

  • Hubble has made more than 1.5 million observations since its mission began in 1990.
  • Astronomers using Hubble data have published more than 19,000 scientific papers, making it one of the most productive scientific instruments ever built. Those papers have been cited in other papers over 1.1 million times.
  • Hubble has no thrusters. To change angles, it uses Newton’s third law by spinning its wheels in the opposite direction. It turns at about the speed of a minute hand on a clock, taking 15 minutes to turn 90 degrees.
  • Hubble has peered back into the very distant past, to locations more than 13.4 billion light-years from Earth.
  • Hubble’s mirror is about 7.9 feet (2.4 m) across. It was so finely polished that if you scaled it to be the diameter of the Earth, you would not find a bump more than 6 inches (15 cm) tall.
Image (Credit): The Carina Nebula. (NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
Image (Credit): NGC 3603. (NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration)
Image (Credit): The Horsehead Nebula, otherwise known as Barnard 33. (NASA, ESA, and the Hubble Heritage Team (AURA/STScI))

A Day in Astronomy: The Death of Yuri Gagarin

Image (Credit): Mourners hold photographs of Gagarin and Seryogin in Red Square on March 30, 1968. (Radio Free Europe)

On this day in 1968, Russian pilot and cosmonaut Yuri Gagarin, who was the first human in space, died in a MIG-15 crash northwest of Moscow. The crash killed a second pilot, Vladimir Seryogin.

Following the accident, President Lyndon B. Johnson issued the following statement:

YURI GAGARIN’S courageous and pioneering flight into space opened new horizons and set a brilliant example for the spacemen of our two countries. I extend the deep sympathy of the American people to his family and to relatives of Colonel Engineer Vladimir Seryogin.

In 2013, The Daily Mail reported that the cause of the crash was an “unauthorised SU-15 fighter” flying too close to Gagarin’s aircraft. Over the years, there had been plenty of rumors about other causes, but this final report appears to put all of these past rumors to rest.

A Day in Astronomy: Discovery of Pluto

Image (Credit): The dwarf planet Pluto. (NASA)

On this day in 1930, Clyde Tombaugh discovered Pluto. The 23-year old astronomer was working for the Lowell Observatory in Flagstaff, Arizona at the time of his discovery.

Pluto, recognized as the ninth planet in our solar system, was demoted to a dwarf planet in 2006 since it was one of many such objects in the Kuiper Belt and did not meet the definition of a planet.

When NASA’s New Horizons spacecraft visited Pluto in 2015, it was carrying some of Clyde Tombaugh’s ashes. The canister with the ashes had the following inscription:

Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system’s “third zone.” Adelle and Muron’s boy, Patricia’s husband, Annette and Alden’s father, astronomer, teacher, punster, and friend: Clyde W. Tombaugh (1906-1997).

You can learn a number of interesting facts about Pluto here.

A Day in Astronomy: The Leviathan of Parsonstown

Image (Credit): The Leviathan of Parsonstown, or Rosse six-foot telescope. (Planetary Society)

On this day in 1845, a 72-inch reflecting telescope built by William Parsons, the 3rd Earl of Rosse, came into use on his estate in Ireland. The telescope remained the largest in the world until 1917, when it was eclipsed by the Hooker reflecting telescope in California.

Known as both the Leviathan of Parsonstown and Rosse six-foot telescope, it was used William Parson to observe star clusters and nebulae. For example, it was used to view a spiral nebula that we know today as the spiral galaxy Messier 51, or The Whirlpool Galaxy, which is about 31 million light years from Earth (see below). You can see The Whirlpool Galaxy today with a pair of binoculars.

Go here for more information on the Earl and his telescope.

Image (Credit): Spiral galaxy Messier 51, also called The Whirlpool Galaxy. (NASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA))