Tag Archives: moon

Plumes Spotted on Europa

Take a look at this image.

Credits: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center
Credits: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center

Just what is this? Well, it’s Europa superimposed on an image of Europa taken by the Hubble Space Telescope. See that white stuff coming from the bottom left? That seems so similar to what we’ve seen from Enceladus. That’s a possible water plume!

So, what does this mean? It means that water is making it to the surface of Europa. This also means that we may have a much easier time accessing the water than we thought. We already have an extremely good idea about the internal structure of Europa, which likely includes a very deep liquid water ocean. Europa is one of the best candidates for life in the solar system, and with upcoming missions to Europa and the other icy moons of Jupiter coming soon, we’ll have an excellent opportunity to know what the composition of this water is. It’s suspected to be salty, but how salty is it? And does it support life?

This is very exciting. What do you think?

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A New Year in Japan – Pre-dawn

It’s already been a while since we got up this morning. We woke up at 4 am, and got ready to go out. We left home around 5:20 am, and walked to the station. We were greeted by very clear skies and a couple wonderful celestial sights.

As soon as we walked out the door, the moon was bright in the sky with Jupiter nearby.

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Walking out to the sidewalk, another bright light was visible. It was the Morning Star, or more correctly, the planet Venus. It was very bright.

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We walked to the station and got on the train. It was full, but we could get on. After a few stations, it was packed like the subway in Tokyo during rush hour. We couldn’t move! Watching the people swaying was like we were all caught in a wave pool, or a train full of sloshing water. Our daughter complained a lot. When we got off the train, the sky was already getting light.

Next post: sunrise from Enoshima!

Mars Will Be Larger than the Full Moon!

Have you heard? It’s that time of year again. Mars will appear larger than the full moon in the night sky! That’s right! Mark your calendar for August 27th! And this is my reaction:

Hahahahahahahahahahahahahahahahahahahahahahahahahahahaha. Excuse me as I wipe the tears from my eyes. Hahahahahahahahaha.

Seriously, how do people fall for this every single year? There are a lot of gullible people in the world. Even though this event has never happened, they still think it will because of something they read on the internet.

First of all, Mars will never be close enough to the Earth to appear larger than the Moon in the sky. Never. Got it? Never. Not going to happen. Ever. Okay?

This all started in August 2003 when Mars made its closest approach to Earth in more than 50,000 years. However, it was a whopping 55,758,000 km away. So people started suggesting it’ll appear large in the sky, so large that it’ll be larger than the full moon. It was actually a misinterpretation of the news, saying that Mars will appear as large as the full moon when viewed through a telescope, not with the naked eye.

But every year people believe this will happen. Let’s look. Here’s Universe Today explaining it. And Phil Plait at Bad Astronomy explaining it. How about Snopes? Or how about NASA themselves? They’re all from different years, but they’re all valid today.

So, people, Mars will never appear as large as the Moon in the sky. Okay? I hope that’s clear.

Ever Watch the Moon Pass In Front of the Earth? Incredible

I saw this earlier. This animation is from several still images of the moon passing in front of the Earth. The images were taken from the DISCOVR spacecraft about 1.6 million km away from the Earth. It’s a quick video, so it won’t take much of your time.

I don’t think there’s ever been a video or set of images like this before.

Just a note about the moon. You may notice that the leading edge is green. This is not because it’s a photoshopped fake. It’s because they take three images in different colours: red, blue, and green.  The green image just happened to be the last one taken, and the moon had already moved a bit, so that’s why it has a green fringe on the leading edge. There’s an argument on Facebook about this, and some people are claiming it’s a conspiracy. Those people just don’t understand how images are made from spacecraft. They don’t just take a colour photo, they take three monochrome photos at three different wavelengths that correspond to red, blue, and green. Then they combine the images to give a true colour image. Since there is a thirty second delay between the three images, this green offset is the result.

Anyway, incredible set of images!

An Ocean on Ganymede

It seems that after I posted about possible life-bearing worlds in our solar system, all these announcements have come out.  Well, now it’s Ganymede’s turn.  Not on my top five list, it may need to be included, though looking at the structure of Ganymede, it’s still a low possibility.

Ganymede_g1_true_2Ganymede is the largest natural satellite in the solar system, even larger than the planet Mercury, but it doesn’t contain as much mass.  The reason is that Mercury has a huge iron core, while Ganymede’s is smaller.  It’s also not common for a moon to have an iron core, and it and Europa are the only two icy moons to be lucky enough.  Ganymede’s molten iron core gives it the distinction of having its own magnetic field, and even aurora.  And it’s just that particular feature that scientists were looking at with the Hubble Space Telescope.  What it enabled them to discover (or rather confirm what has been guessed) that Ganymede has a very thick salty ocean that is 100 km deep.  That means that it has more liquid water than Earth does.  That is quite remarkable.

So what does this mean for life on Ganymede?  Well, considering that the ocean layer is sandwiched between an icy crust and an ice mantle, I don’t think there’s much of a chance of hydrothermal vents.  More like no chance.  That ice mantle is extremely thick.  This differs from Europa in that the smaller icy moon has a liquid water ocean over a rocky mantle.  Europa has a far better chance at having hydrothermal vents and life.  But it’s still very interesting, and I’m really enjoying the recent discoveries.

You can read a full writeup on this at The Planetary Society.

The Solar System One Probe at a Time

In honour of Dawn’s successful orbit of Ceres and New Horizons’ flyby of the Pluto-Charon system in July, I thought I’d take you all on a tour of the solar system one probe at a time.

What does this mean?  I’m going to go all the way back to the first lunar probe, Luna 1 in 1959, and talk about each probe that was launched from Earth in chronological order.  I’ll look at what they achieved, what they saw, and what happened if they failed.  I’ll even include the ones that never made it out of the atmosphere and crashed back into the ocean.

I will not look at any spacecraft that were only intended to orbit the Earth.  I’ll look at every probe that went to the moon, the planets, asteroids, comets, and even the sun.  Just anywhere but Earth.

I will provide some pictures when available of the probe, as well as some things they took photos of.  I may even embed the launch videos if I can find them.

I hope you’ll enjoy this look back through the history of solar system exploration.