Tag: Venus

Time lapse: When the Moon ate Venus

By Phil Plait | August 31, 2012 6:30 am

On the morning of August 13 – 14 (depending on where you were in the world) the Moon slipped directly in front of Venus in the sky, an event called an occultation. It was cloudy here in Boulder so I missed it, but halfway across the world in Korea, astrophotographer Kwon O Chul had a magnificent view, and made this lovely time lapse video of the event.

Occultations like this are relatively rare. If all the planets and moons orbited the Sun in exactly the same plane – that is, if you looked at the solar system from the side and all the orbits aligned perfectly, like looking at a DVD from the side – we’d see occultations all the time.

But in reality all the orbits are tilted a little bit. Venus circles the Sun in an orbit canted by about 3° compared to Earth’s. The Moon’s orbit is tilted by 5 °. The Moon orbits the Earth once per month or so, but it usually passes by Venus, missing it by a bit because the orbits aren’t aligned. But sometimes, every few years, the dance comes together, and the Moon wil slip directly in front of Venus.

An occultation is an amazing thing to see. I saw a lunar Venus occultation when I was a kid and just starting out as an amateur astronomer. It takes a few seconds for the Moon to cover a planet, so you can watch as the planet dims and then pops out when it gets completely covered. Also, the Moon commonly passes in front of stars, which are so far away and appear so small they just wink out, blip!

You can get a list of upcoming occultations at the International Occultation Timing Association website. If you get a chance to see the Moon occult a star, take it! Binoculars help a lot, and it’s fun to watch the star just suddenly blink out.

Tip o’ the dew shield to Astropixie.

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Planetary alignment pyramid scheme

By Phil Plait | August 20, 2012 12:46 pm

What the heck is in the air this past week? First we see a simulated image of the sky from Mars go massively viral because people thought it actually showed Earth in the Martian sky, then a clearly Photoshopped pic of two "Suns" setting on Mars gets passed around.

And now a new slice of oddness enters the field: a picture of a planetary alignment over the Giza Pyramids, saying this only happens once every 2737 years. Because planetary alignments and the pyramids play such a large role in New Age/astrological beliefs, there is clearly some sort of spiritual message implied here.

Well, I hate to be a thricely-bursting-bubble person, but here we go again, again. Let me be clear: while there will be an event more-or-less like this in December, and it should be pretty and quite cool to see, the claims being made are somewhat exaggerated. The picture itself isn’t real, and the planets won’t really look like that from Giza. Also, alignments like this happen fairly often, though to be fair getting them spaced out to fit over the pyramids in this way probably is relatively rare.


Busting your Cheops

Here’s the picture making the rounds:

It clearly shows the three pyramids in Giza, Egypt, with three planets above them. There are various versions of this picture I’ve seen; most are like this with almost no explanation. Some say the planets are Mercury, Venus, and Saturn, and some mention this is what it will look like on December 3rd, 2012, just before sunrise.

First, this obviously cannot be an actual photo if the event hasn’t happened yet! This must be a Photoshop job. That’s fine if it’s only to show what things are supposed to look like, and no one is claiming this is an actual photo.

However, it hardly matters. There are lots of other problems with this planetary alignment claim.


What’s your angle?

The first thing I did when I saw this was ask: is there really going to be a close conjunction of three planets on December 3rd?

The answer is yes! Mercury, Venus, and Saturn will all be within a relatively small distance of each other in the sky on that date. This isn’t a particularly tight configuration like Venus and Jupiter were earlier this year – in this case, they’ll be 14 degrees apart, nearly 30 times the width of the full Moon on the sky – but it’s still pretty nifty.

The second thing I did, though, was ask myself: will they really look like that in the sky as seen from Giza?

The answer this time is no. I used the software planetarium program SkySafari to show what the three planets would look like in the sky before sunrise on December 3rd as seen from the location of the pyramids, and got this:

In this picture, the yellow line is the ecliptic, the path of the Sun in the sky through the year. The green horizontal line is the horizon, and the three planets are labeled.

Note the angle of the planets: in the picture going viral, the planets are much closer to horizontal, but in reality the line connecting the planets is at a much steeper angle. It’s nearly vertical, in fact. This may not seem like a big deal, but having the planets closer to horizontal like in the viral picture is more spectacular than what will really happen, exaggerating the claim.

Not only that, but in the pyramid picture the planets are almost exactly on a line, like beads on a string. But as you can see in the picture above, they’re not nearly that colinear. Again it’s looking like the pyramid picture is exaggerating the situation.


Mirror, mirror

I noticed something else funny as well.

Here’s a satellite view of the three pyramids, courtesy Google maps:

Read More

An unreal Mars skyline

By Phil Plait | August 10, 2012 9:59 am

Well folks, it’s been a while, so it’s time for a good ol’ fashioned BA debunking.

This morning I got an email from BABloggee Joshua Frost as well as a note on Twitter from scifi author Diane Duane telling me about a picture making the rounds on teh interwebz, purporting to be taken from Mars. It shows the Martian landscape at twilight, and claims that the three lights in the sky are Earth, Venus, and Jupiter:

Pretty, isn’t it? You can find endless copies of it online; just search on the term "mars skyline". It’s been picked up on tons of Tumblrs and other social media.

But yeah, there’s just one problem: it’s not real.

I knew right away it wasn’t legit, but it’s hard to say exactly how. I’ve run into this problem before; I have a lot of experience looking at space images, and you just get a sense of what’s real and what isn’t. This one screams fake. The landscape color is a bit too saturated for Mars*. The sky’s the wrong color. The clouds are too numerous, the wrong color as well, and they have that "rendered by software" look to them.

But that’s not proof, of course. Gut sense may not be a bad place to start, but it makes for lousy evidence. The thing is, there is solid evidence the picture isn’t real! Look to the lower left corner of the image; see the letters there? Here’s a zoom:

See? The arrow points to the letters, and I zoomed in and enhanced the brightness and contrast a bit. The letters are "NE". As in, "northeast".

This is exactly what you see when you use planetarium software on a computer to display the sky. Programs like Starry Night, SkySafari, and so on will put the cardinal directions (north, south, and so on) along the horizon to indicate what direction you’re looking. And many of them will display the appearance of the sky from other planets. It’s clear that’s what we have here: a rendered view from Mars using planetarium software. I’m not sure which one (there are quite a few packages available) but I bet someone out there in BAland would recognize it. Any takers?

Interestingly, fiddling with some of software I have that displays solar system planetary positions, I found that a couple of years ago (mid-2010) the view from Mars right after sunset would show Venus, Earth, and Jupiter lined up something like that. Had you been on Mars looking west you would’ve seen something very much like the vista in the picture. Thing is, had one of the rovers taken this picture, it would’ve been all over the web at the time… including here on Bad Astronomy. I wouldn’t have passed up the chance to post a picture that cool. [Note: there is a real picture of the Earth seen by a Mars rover: from Spirit, in 2004, inset above.]

Mind you, the picture itself isn’t a hoax! It’s just a computer generated image probably meant to represent a real scene. But it got spread around the net, and before you know it people think it’s real.

I’ll note that I love that people think images like this are so beautiful and interesting that they pass them around and get a sense of wonder from them. But it bugs me that it’s possible that an unreal picture gets treated as real. In this case there’s no harm done, but it’s not hard to imagine a case where a forged image showing something damaging to someone’s reputation gets treated as real and spreads like wildfire. It’s happened before, many times.

The problem here is that people pass it from one place to another without attribution, without a link to the original source (usually it’s linked to the place they got it from, one link down the line in a very long chain). In this case, I searched for a while and still have no idea where the original for this came from. It got picked up wholesale from blog to blog and Tumblr to Tumblr so rapidly that the pedigree of it got lost. Maybe someone more patient than me can find the source.

I’ve been fooled on Twitter by fake posts before, too. Everyone has at some point. I’m just glad to be able to interject a little dose of reality in this case.

And remember: we have actual, real, amazing, breath-taking images coming from Mars right now. And the fact that they are real, and mean we have a presence on another world, is far more moving and stirring than any fake could ever be.


* I’ll note that the color of the landscape in the picture does look similar to that from the old Viking images of Mars from the 1970s. The color of those images was probably too saturated when displayed, in my opinion; getting the color right in those old shots was actually fairly tough.


Related Posts:

- An unreal picture of sunset at the north pole
- A fake and a real view of the solar eclipse… FROM SPACE!
- NASA FAKED A SHUTTLE IMAGE!!!!! (a joke post I put up that some folks took seriously; see the followup post for more silliness)
- Holy UFO hoax!
- Latvian meteorite impact: fake

CATEGORIZED UNDER: Debunking, Pretty pictures, Skepticism

Transit on the Midnight Sun

By Phil Plait | June 20, 2012 10:00 am

Because why not, I have two more Venus Transit shots to show you. Well, one picture and one quick time lapse video. I know it’s been a couple of weeks since the transit, but since today is the solstice, what the heck. And these are really special.

The first is a picture taken by friend-of-the-blog Babak Tafreshi, who founded and directs the wonderful project The World at Night, which shows people how lovely our skies are. He took several shots of the transit from Norway and put them together into this gorgeous composite photo:

[Click to ensolarnate, and you really need to; I had to shrink it quite a bit to fit the width of the blog.]

I love this shot, because…. he took it at midnight! From northern Norway in June the Sun doesn’t set; it skims the horizon at midnight, circling nearly parallel to it for a time. This coincided with the transit, making this one of the single most interesting sequences of the transit I’ve seen. I also like how the Sun went behind a hill there on the right, with Venus and a sunspot still peeking over the edge. Babak says he’s working on a time lapse video of the event too. [This picture was also on today's APOD.]

Speaking of which, the second transit shot is a time lapse video sent to me by Mark Ellis (who took the pink aurora picture I posted yesterday). He took this sequence in Minneapolis as Venus crossed the Sun’s face:

Short, but neat! I also like the music; it was written by Mark’s son Ryan. It fits the feel of the video very well.

I love these time lapse videos of the transit. The Sun is setting due to the Earth spinning on its axis, and Venus transiting the Sun due to its orbital geometry combined with our own. I like to picture all that motion in my head as I watch Venus silhouetted on the setting Sun, imagining myself affixed to a spinning world whirling around a star with other attendant worlds, all of us in a constant and complicated dance, moving to the tune of gravity.

How wonderful it is that we can understand and appreciate this celestial clockwork!

Image credit: Babak Tafreshi/Dreamview.net/TWaN


Related Posts:

- The June 2012 Transit of Venus Gallery
- Astronomer’s paradise (and Making "Astronomer’s Paradise")
- How could I NOT post this Venus transit picture?
- Sic Transit, Glorious

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Towering transit of Venus

By Phil Plait | June 14, 2012 7:00 am

OK, look, I know I’ve posted a lot of Venus Transit pix, and it’s been a week now, so you have to know I wouldn’t post one this late unless it was really awesome.

I present to you really awesome… Part 1:

Wow! This was taken by friend-of-the-BABlog Alan Friedman. To shoot this video he used a filter that lets through light from hydrogen, and that shows lots of solar activity like sunspots and filaments. The video is a negative, which makes it easier to see faint details on the surface, and which makes Venus look white instead of black. But I like how he kept his telescope centered on the Sun as it set, so it looks like it’s the tower moving into the field of view instead of the usual shot of the horizon held steady while the Sun sets. Very cool.

[Update: For those asking about the tower, Alan sent me this photo to clear things up.]

But he did more than take video: he took his usual jaw-dropping, stunning, ridiculously cool photos as well, like this one… really awesome, Part 2:

[Click to ensolarnate.]

Yegads. Read More

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Venus orbital plane

By Phil Plait | June 10, 2012 7:03 am

Local (to me) photographer Patrick Cullis was filming the Venus Transit last week from Colorado, and got a surprise:

Pretty cool. That’s part of a longer video he made of the transit that’s nice, too.

While I’m at it, he made a really pretty time lapse of the sky over Boulder, including footage of Venus and Jupiter setting over the Flatiron mountains; it’s well worth a moment of your time to watch. You can see the moons of Jupiter, too!

http://vimeo.com/42052493

The Flatirons are huge slabs of rock hundreds of meters high that used to be seabed, but were pushed nearly vertical when the Rocky Mountains broke through. They make a stunning backdrop to these videos by Patrick, too.

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Interloper of the Venus Transit

By Phil Plait | June 7, 2012 9:39 am

I figured I was done posting Venus Transit pictures, but I should’ve realized I hadn’t heard from Thierry Legault yet. And as soon as I saw his name in my email Inbox this morning, and before I even opened it, I knew I’d have at least one more picture to show you.

And I was right. Thierry is a master astrophotographer, and he’s not one to just let an astronomical event go by without figuring out some way to make it even cooler. He traveled to northeast Australia to view the Venus transit… not just because it had a good view, but also because from there, he could see the Hubble Space Telescope transiting the Sun at the same time! On June 6th, at 01:42:25 UTC, he got this amazing shot:

Holy wow! [Click to doubletransitenate.]

You can see Venus as the big black circle, as well as dozens of sunspots. But you can also see multiple images of Hubble as it zipped across the Sun, circled in the image above. Orbiting the Earth, Hubble moves across the sky so quickly that it crossed the Sun in just under a second. Blasting his DSLR away at ten frames per second (and with an exposure time of only 1/8000th of a second per frame) Thierry managed to get 8 shots of Hubble silhouetted against the Sun.

Here’s a bit of a close-up:

I added the arrows to help you see Hubble. The orbiting telescope was about 750 kilometers (450 miles) away from Thierry when he took these pictures (it was not directly overhead), so details on Hubble are too small to capture, but it can be seen as a black dot.

Theirry’s done this before, too: in January 2011, he got an astonishing picture of the space station crossing the Sun during a partial solar eclipse! His ability to time these events and get pictures like these is nothing short of amazing.

He also says he got more pictures, too, including some of Venus just as it was entering the Sun’s face. Hopefully he’ll have those available soon! In the meantime, click the links below under Related Posts to see more of his ridiculously cool photos.

Image credit: Thierry Legault, used by permission.


Related Posts:

- China’s space lab has a spot in the Sun
- Doomed ROSAT captured in video
- Atlantis, one last time in the Sun
- SERIOUSLY jaw-dropping pictures of Endeavour and the ISS!
- INSANELY awesome solar eclipse picture

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

How could I NOT post this Venus transit picture?

By Phil Plait | June 6, 2012 2:31 pm

I wasn’t going to post another Venus Transit shot, because my mousing arm still hurts from putting together the gallery for this morning.

But holy geez, I saw this, and c’mon!

I mean, seriously. Wow. [Click to cythereanate.]

This image of Venus as it entered the Sun’s disk was taken by the NASA/JAXA (Japanese space agency) spacecraft Hinode on June 5. The detail is breathtaking. The ring around Venus is due to scattering and refraction — light from the Sun passes through the upper part of the Venusian atmosphere and gets bent toward us. You can also see some texture on the Sun’s surface (really packets of hot gas rising and cool gas sinking) and some nice prominences off the Sun’s limb — material lifted against the Sun’s massive gravity by its equally ridiculously strong magnetic field.

That’s a whole planet there, folks, nearly the same size as Earth, roughly 40 million kilometers (25 million miles) from Earth, back lit by a star 110 million km (70 million miles) farther away yet and well over 100 times bigger than Venus!

And we knew about it, predicted it, aimed our machines at it, and observed it so we can learn more and see more beauty. The things we humans do when inspired by the Universe. Amazing.

Image credit: JAXA/NASA/Lockheed Martin

CATEGORIZED UNDER: Astronomy, NASA, Pretty pictures
MORE ABOUT: Hinode, Sun, Venus, Venus transit

Sic Transit, Glorious

By Phil Plait | June 6, 2012 10:44 am

This is what I’ve been waiting for: the stunning video views of NASA’s Solar Dynamics Observatory of the Venus transit. Sit down, set this video to high-def, tune out everything else for 3 minutes 7 seconds, and soak in the clockwork glory of our solar system.

OK, you can breathe now. NASA has provided high-resolution versions for download, too.

SDO orbits the Earth about 40,000 kilometers (24,000 miles) above the surface of the Earth, with a nearly-continuous view of the Sun — so it had the best seat in the Universe for the transit. One of its most important tasks is to observe the Sun in ultraviolet, where our star’s magnetic activity is most obvious. The views in the video show the Sun different parts of the ultraviolet spectrum, colored to make them easier to see: magenta is at 1700 Angstroms (a unit of length astronomers like; 100 million Angstroms would comfortably fit across your fingernail), red is 304 Angstroms, and gold is 171 Angstroms. The orange segment is from the light we can see, about 3000 – 7000 Angstroms.

The Sun’s ethereal outer atmosphere, its corona, glows at at 171 and 304 Angstroms. In visible light the transit lasted about 7 hours, but in the UV it took longer since the silhouette of Venus can be seen against the softly luminous corona.

SDO was commanded to take images faster than usual, to provide as much coverage of the transit as possible, so the passage of the planet across the Sun is smooth and — I know, but it fits — other-worldly.

And I can’t help but think about a sad milestone today: one of America’s — one of the world’s — greatest writers, Ray Bradbury, has died. Among his many works was "The Long Rain", a short story which took place on Venus. It had a huge impact on me when I first read it as a kid, and it still makes me think about human nature, space exploration, and what happens when we mix the two.

Bradbury was more than a writer, he was a poet, and his works inspired generations of people to look beyond the borders of our world while still considering our humanity. We all must go someday, and for him to do so on the eve of the last transit of Venus to be seen for over a century is, somehow, fitting.

Ray Bradbury knew that no matter where we are, whether we are looking down into the water of another world, or looking up into the skies, what we are always seeing is a reflection of ourselves.

Sic transit gloria mundi.

Credit: NASA/SDO

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

The June 2012 Transit of Venus Gallery

By Phil Plait | June 6, 2012 5:30 am
trees
titlepage
michaelhess_binoceyes
lindsaymiller_hatbrim
iss_squishy
laurentjolicoeur_sunset
ingrum_lick
josemtanous_toddler
adamwolny_plane
austinpowers
crescent
spencersmith_plane
sdo_composite
sdo_aia304_transit
sdo_171_venustransit
robford

MORE ABOUT: Sun, Venus, Venus transit
NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »