Milestones in Astronomy: 1995 to Present

Throughout the 1990s, astronomers learn more about the planets in the Solar System, thanks to the satellite probes sent into space. Details are revealed about Jupiter, Mars, and Saturn,. In this article, you will learn about advancements in space stations, observatories, and spacecrafts.

1995 , The unmanned Galileo probe makes its way to Jupiter. NASA sends the spacecraft to study the planet and its moons. Launched in 1989, it takes the probe a little over six years to reach Jupiter. The probe has reported antenna issues, but is still able to conduct the first asteroid flyby near 951 Gaspra. It also discovers the first asteroid moon called Dactyl. Other tasks that the spacecraft is known for is measuring the atmospheric composition of Jupiter, directly observing ammonia clouds in the atmosphere of the planet, and highlighted details that shed light on the liquid oceans theories. It was Galileo that also offered observations on the Shoemaker Levy comet impact on the atmosphere of Jupiter.

1997 , The Mars Pathfinder lands and is at the center of a mission involving the planet Mars. The mission included the use of rovers. Scientists had a variety of objectives, but also wanted to test out a lot of new technologies. Some of the concepts they tested were the airbag-mediated touchdown and automated obstacle avoidance.

1997 , The launching of the Cassini probe takes place. It is on its way to Saturn. Interestingly, Cassini is powered by Plutonium 238. The heat from the radioactive decay is transformed into electricity. Some of the instruments associated with Cassini included the Cosmic Dust Analyzer (CDA) and Composite Infrared Spectrometer (CIRS). The CDA is a direct sensing instrument that measures the size, speed, and direction of tiny dust grains located close to Saturn. The CIRS is a remote sensing instrument that measures the infrared waves that come from objects as a way to learn about their temperatures, thermal properties, and makeup.

1998 , The construction of the International Space Station (also known as ISS) begins. The research facility becomes the largest space station ever constructed. On-orbit construction of the station started in 1998 and when completed is expected to stay in operation until at least 2020. The ISS can be seen from Earth with the naked eye. The purpose of the facility is to conduct experiments in the fields of biology, physics, astronomy, and meteorology.

1999 , In July, the launching of the Chandra X-Ray Observatory takes place. The satellite was named to honor a physicist who determined the maximum mass for white dwarfs. Interestingly, ‘Chandra’ also means ‘moon’ or ‘luminous’ in Sanskrit. The Chandra Observatory is the third of what is known as NASA’s Great Observatories , four in total. Chandra joins the Hubble Space Telescope, compton Gamma Ray observatory, and the Spitzer Space Telescope.

2003 , Galileo probe deliberately crash lands on Jupiter as it is deorbited at this time. Up until then, it had transmitted scientific data for years. The last scientific experiment that Galileo performed was to measure the mass of the moon Amalthea as the spacecraft passed by it.

2006 , New Horizons space probe launches to Pluto, which is the first probe to the dwarf planet.

2008 , The Phoenix mission to Mars lands on the planet. This robotic spacecraft was sent to explore Mars under what was called the Mars Scout Program. Mission scientists used instruments aboard the lander to seek out environments that are suitable for microbial life on Mars. They also wanted to research the history of water on the planet.

2009 , In this year, the 400th anniversary of the astronomer Galileo’s first telescope observations is celebrated.

2011 , The first probe sent to Jupiter without atomic battery power is launched on August 8, 2011. It is called Juno.