For a lot of people, exoplanets are some of the most exciting discoveries in current astronomy. The first exoplanets were detected in 1992 orbiting the pulsar PSR B1257+12, all three of which were confirmed in 2007. In 1995, 51 Pegasi became the first main sequence star to have an exoplanet detected around it. In the years since, interest in exoplanets increased as they became easier to discover and there are now seventy-four NASA-confirmed planets outside our solar system, and thousands more are under close watch to see if they’ll make the cut. But long before we knew for sure they were there, even centuries before the excitement within the field today, astronomers wondered if there were any “other earths” out there – and a lot of them were confident that there were! As it turns out they were right, but a lot of what people hear about exoplanets (or exosolar planets, or extrasolar planets, pick your flavor) doesn’t come from scientific sources, which can breed some interesting discrepancies between science-fiction and science-reality. Read more »
Posts tagged: voyager
Voyager is soon to be the first man-made object to leave the solar system. Data from NASA’s Voyager 1 spacecraft indicate that this deep space explorer has entered a region in space where the number of charged particles from beyond our solar system has significantly increased. This could mean that Voyager 1 may be at the edge of our solar system and about to leave it. The spacecraft Voyagers 1 and 2 were launched in 1977, originally designated to study Jupiter and Saturn, but have since continued their journey on to study the outer solar system. The image above depicts where the Voyager spacecraft are in relation to our solar system and the surrounding area.
The Voyager team is looking at a few specific things that they expect will tell them when the spacecraft has punched through the ‘heliosheath’ – a kind of bubble around our solar system where stellar winds slow down dramatically. First, a great increase in the number of galactic cosmic rays (energetic charged particles from outside our solar system). The numbers appear to be on the rise, which is a good sign that Voyager 1 is getting close to the heliosheath. The team is also looking at the intensity of energetic particles from inside the heliosphere. These have been steadily decreasing but have yet to drop off abruptly, as would be expected when the craft leaves the heliosphere. Lastly, there is the measurement of the direction of the magnetic field lines surrounding the spacecraft. Currently, while the craft remains in the heliosphere, the field lines run east-west. However, when it passes into interstellar space, it is thought that the field lines will switch to running more north-south. There is still much analysis of the data to be done, but we can still expect that one day Voyager will be our first man-made ambassador to interstellar space.
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