Earth passed between sun and Pluto yesterday
9 comments Print Me Email to FriendTonight is Saturday, Jun 21 2008
Pluto – the former planet – came to opposition yesterday, June 20, 2008. That is when we on Earth passed more or less between the sun and Pluto, so that this distant world is now opposite the sun in our sky.
Of course, in Pluto’s case, it’s not exactly opposite since the orbit of Pluto is inclined to the plane of the solar system by 17 degrees. That’s a greater inclination than the orbits of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus or Neptune … and it’s one thing that has always set Pluto apart. Pluto’s differences ultimately lost this world its planet status, according to a 2006 decision by astronomers of the International Astronomical Union.
Pluto is closest to us now for the year at just over 4 light-hours away. And, because it’s most nearly opposite the sun, Pluto does rise within about half an hour of sunset on June 20. This mysterious world is now highest in the south when the sun is below our feet at midnight. It is not possible to see Pluto with the eye. Pluto is some thousand times too faint to be viewed with the eye alone. But the bright planet Jupiter is near Pluto on the sky’s dome. So if you see Jupiter around now, you can imagine Pluto’s location.
Each opposition of Pluto brings it closest and brightest for the year. Yet Pluto is not as close to us at this year’s opposition as it was last year. Pluto was closest to the sun in its 248-year orbit in 1989. Throughout the 1980s and 1990s, it was closer to the sun than Neptune. Thus Pluto was closer to us – and brighter than it is tonight – at its oppositions during those years. It is now farther away from the sun – and thus from us – at each successive opposition.
Hello. Is it possible to see Pluto with a pair of binoculars? If not, what is the minimum in a telescope that one would need? Thanks JR
Joe,
According to Sky & Telescope magazine editor Alan MacRobert, you need at least an 8 or 10-inch reflector telescope and a dark sky to see the dwarf planet Pluto. Even at that, this distant world only appears as a faint speck of light.
Pluto is well over a thousand times fainter than the dimmest star that you can see with the unaided eye!
Bruce
hi…do you agree with the international astronomical union that pluto is no longer a planet if so why…i dont i still consider pluto the ninth planet
Regarding Joseph Molinaro’s comment: Does it really matter what status we give to Pluto? What we call it is completely arbitrary considering that it is still a hunk of rock and ice of a certain size with a certain orbit. Our knowledge changes much faster than any celestial body.
thank u from france to create this website that i just know, does it exist in french language? thanks
thank u from france to create this website that i just know, does it exist in french language? thanks
Joe & Random,
Pluto never fails to generate a response! To the best of my understanding, a solar system body is a planet if:
1) that body has enough mass to display a globe-like shape (hydrostatic equilibrium)
2) that body isn’t a moon of a planet
3) that body has sufficiently cleared its orbital zone
Pluto meets the first two criteria but not the third. In my opinion, the vague “clearing of the body’s orbital zone” condition may need to be revisited. For more opinions, read Who else wants Pluto to be a planet again?
Sevda,
No French Earth & Sky as of yet, but the recently posted Spanish version is now available.
Bruce
Theres a huge white spec in the sky, over leeds UK, its not moving and is so bright that no other stars are seen at this time (its getting close to sun rise), hope its not a huge meteor coming towards earth!
Kostya,
It’s my guess that you’re looking at the planet Jupiter, which easily outshines the brightest stars in the sky. Except for the moon, Jupiter is the brightest celestial body to light up the nighttime throughout June and July. In early July, Jupiter will be out from dusk till dawn, appearing low in your southeastern sky at nightfall and low in the southwest at daybreak. For more, check out the upcoming radio show on Jupiter.
Bruce