Looking back: 1982

In 1982 (35 years ago!) I finished my basic undergraduate degree, majoring in Mathematics and Computer Science (after sniffing around the job market, I continued my studies for an honours year). This was the year that the compact disc and the Commodore 64 computer came out:

Also that year, Stephen Cook won the Turing award for his work on computational complexity theory. The then Soviet Union landed two spacecraft in the hellish inferno that is Venus, and took photographs:

It was also a year of conflict – Argentina started a war with the UK over the Falklands Islands, and Israel invaded Lebanon. On a more positive note, there were several movies which became cult classics, such as Tron, E.T., and Conan the Barbarian. The superb science fiction movie Blade Runner stood out from the crowd (even with the flaws in the original cinema release):

In literature, Isabel Allende published her debut novel, as did Kazuo Ishiguro. In music, The Alan Parsons Project released their album Eye in the Sky and Australian band Icehouse (originally Flowers) released their classic single “Great Southern Land”:

Overall, it was a great year (apart from the wars).


Spaceprobes in the Solar System

The diagram above (click to zoom) and list below show currently active spacecraft in the Solar System, not including those operating close to the Earth (and I’ve probably missed a few):

  • Voyager 1 and Voyager 2, launched in 1977, now heading into the darkness and still reporting back, even though they are over 17 billion km or 16 light-hours away (not shown above).
  • Cassini–Huygens, launched in 1997, now in the final stages of its exploration of Saturn (see fact sheet).
  • 2001 Mars Odyssey, launched in 2001, and still orbiting Mars.
  • New Horizons, launched in 2006, now en route from Pluto to the Kuiper belt object 2014 MU69, which it should reach in January 2019.
  • Dawn, launched in 2007, currently orbiting Ceres (image shown above the Earth).
  • Akatsuki, launched in 2010, currently orbiting Venus, which it will do until 2018.
  • Juno, launched in 2011, currently orbiting Jupiter, which it will do until February 2018.
  • Hayabusa 2, launched in 2014, currently en route to asteroid 162173 Ryugu, which it should reach in 2018. It will then take a sample which should arrive back home in 2020 (not shown above).
  • ExoMars Trace Gas Orbiter, launched in 2016, currently orbiting Mars and mapping the Martian atmosphere (the associated Mars lander was lost in 2016).
  • OSIRIS-REx, launched in 2016, currently en route to asteroid 101955 Bennu, which it should reach in 2018. It will then take a sample which should arrive back home in 2023 (image shown below the Earth).

In addition to the above, BepiColombo is scheduled to launch for Mercury in October 2018, and SolO is scheduled to launch for the Sun that same month. Also, InSight is scheduled to launch for Mars in May 2018, and Solar Probe Plus is scheduled to launch for the Sun in August 2018.

Venus and Jupiter in conjunction

The planets Venus and Jupiter were in conjunction last night, as the photograph above (by Neal Simpson) shows. The diagram below (by the Fourmilab) shows why: although Venus is much closer to Earth (and thus much brighter), the three planets are almost in a straight line. Venus and Jupiter should still be pretty close in the sky for the next few nights.

Surface areas of the solar system

Here is another gem from XKCD: surface areas of the various solid objects in the solar system – excluding the gasballs Jupiter, Saturn, Uranus, and Neptune, but including their moons (click to zoom). As might be expected from images of the planets, Earth and Venus have the lion’s share of the real estate:

Venus nears inferior conjunction

The planet Venus is about to reach inferior conjunction, the point of closest approach to Earth. Currently, Venus is 43.8 million kilometres (27.2 million miles) away. In a telescope, it is visible as a large, thin crescent – this video (by Stanko Jankovic) shows the planet on December 22nd:

For the current distance to Venus, see Wolfram’s calculator or the live diagram of the solar system at Fourmilab, which includes images (green lines show orbits below the plane of the ecliptic):

Live Solar System image

The planets, to scale

The above edited NASA image from 2006 shows Mercury, Venus, Earth, and Mars, to scale. Yellow bars show the range of distances from the Sun. There is a more three-dimensional view here.

Even nicer is the image below (a team effort; click on the image for details). It shows (top row) Uranus and Neptune; (second row) Earth, the white dwarf star Sirius B, and Venus; (third row) Mars and Mercury; and (fourth row) the Moon, Pluto, and the dwarf planet Haumea. The last five are shown in more detail here.

Also displaying the orbits to the same scale is more difficult, but a variety of exhibits manage to do that, including a 10-kilometre-long model of the solar system in York, England.