Tag Archives: JPL

Cassini’s historic dip into the ocean of Enceladus

31 Oct

On October 28, 2015 Cassini passed below (above?) the south pole of Enceladus at an altitude of 49 kilometers. The probe was flown here in order to get a taste of the water-ice particles that are streaming out into space from Enceladus’ suspected sub-surface ocean in this location. This is the lowest pass Cassini has made through the alien ocean geyser.

This was done in order to help scientists understand the nature of the ocean, how close to the surface it might be, and if the water contained in it could accommodate life. Also of particular interest, the Cassini team is looking for a particular chemical signature of hydrogen that could support the theory that Enceladus has hydro-thermal vents heating water deep in the moon’s ocean.

Related reading: Water, water everywhere!

It’s important to note, however, the instruments Cassini carries on board can characterize the chemical composition of any particles it encounters, but it doesn’t have the ability to directly test for life.

The detailed analysis of the tiny water droplets that Cassini caught as it flew through the plume is now underway (with full results a few weeks away), but some images of the fly-by have already been sent back. And as we’ve come to expect from Cassini, they’re spectacular.

The south polar region of Saturn's active, icy moon Enceladus awaits NASA's Cassini spacecraft in this view, acquired on approach to the mission's deepest-ever dive through the moon's plume of icy spray. The wavy boundary of the moon's south polar region is visible at bottom, where it disappears into wintry darkness. CREDIT: NASA/JPL-Caltech/Space Science Institute

The south polar region of Saturn’s active, icy moon Enceladus awaits NASA’s Cassini spacecraft in this view, acquired on approach to the mission’s deepest-ever dive through the moon’s plume of icy spray. The wavy boundary of the moon’s south polar region is visible at bottom, where it disappears into wintry darkness. CREDIT: NASA/JPL-Caltech/Space Science Institute

A RAW and unprocessed image from Cassini as it flew towards the icy plume at Enceladus' south pole. CREDIT: NASA/JPL-Caltech/Space Science Institute

A RAW and unprocessed image from Cassini as it flew towards the icy plume at Enceladus’ south pole. CREDIT: NASA/JPL-Caltech/Space Science Institute

During its closest ever dive past the active south polar region of Saturn's moon Enceladus, NASA's Cassini spacecraft quickly shuttered its imaging cameras to capture glimpses of the fast moving terrain below. This view has been processed to remove slight smearing present in the original, unprocessed image that was caused by the spacecraft's fast motion. CREDIT: NASA/JPL-Caltech/Space Science Institute

During its closest ever dive past the active south polar region of Saturn’s moon Enceladus, NASA’s Cassini spacecraft quickly shuttered its imaging cameras to capture glimpses of the fast moving terrain below. This view has been processed to remove slight smearing present in the original, unprocessed image that was caused by the spacecraft’s fast motion. CREDIT: NASA/JPL-Caltech/Space Science Institute

Following a successful close flyby of Enceladus, NASA's Cassini spacecraft captured this artful composition of the icy moon with Saturn's rings beyond. This view looks towards the trailing/anti-Saturn side of Enceladus. North is up. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 28, 2015. The view was acquired at a distance of approximately 171,000 km from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 141 degrees. Image scale is 10 km per pixel. CREDIT: NASA/JPL-Caltech/Space Science Institute

Following a successful close flyby of Enceladus, NASA’s Cassini spacecraft captured this artful composition of the icy moon with Saturn’s rings beyond. This view looks towards the trailing/anti-Saturn side of Enceladus. North is up. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 28, 2015. The view was acquired at a distance of approximately 171,000 km from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 141 degrees. Image scale is 10 km per pixel. CREDIT: NASA/JPL-Caltech/Space Science Institute

A new photo of home: Earth as seen from Mars in January 2014

15 Feb

In March 2004, the Spirit rover on Mars captured the first image of Earth ever taken from the surface of another planet.

A couple weeks ago, NASA’s newest Mars rover accomplished the same feat, snapping a photo of the Earth and the Moon in the sky of another world.

The Mars Science Laboratory (aka Curiosity) captured this image on the evening of January 31, 2014 from inside the Gale Crater on Mars. The image was taken using the left eye camera of Curiosity’s Mast Camera (Mastcam) about 80 minutes after sunset. Mars and Earth were 160 million kilometers apart when the photo was taken.

You, along with everyone you have ever known or heard of, is here. (click image for larger version)

You, along with everyone you have ever known or heard of, is here. (click image for larger version)

(Click here to download 18mb TIFF file)

If (when) a human is on Mars and looks up into the sky, they’ll see Earth and the Moon as two evening or morning stars – similarly to how Venus appears in the evening and morning sky here on Earth.

In this photo taken by Curiosity, the Moon appears just below the Earth as a fainter, though still distinct, object.

I particularly enjoy photos like this due to rare the perspective it affords us. To be able to see our entire world, our “vast” civilization, take up only a few pixels in an image from another world is an important reminder that we are apart of something much larger.

It makes our problems and petty differences here seem less significant.

It provides inspiration for us to aim for bigger, better things.

Keep ’em coming, NASA. We all need to see things like this more regularly.

Earth & Moon - the bright objects in the sky - as seen from Mars by the Curiosity Rover on January 31, 2014

Earth, as seen from Mars, by the Curiosity Rover on January 31, 2014

And not to be forgotten is the famous Pale Blue Dot image captured by Voyager 1 from a distance of six billion kilometers in 1990.

New mystery rock shows up in MER-Opportunity photo

22 Jan

Just ahead of it it’s 10th birthday on the red planet, Opportunity has started a discussion around new rock!

Two images taken of the rover’s work area, taken two weeks apart, show that a new doughnut-sized white rock has appeared – apparently out of nowhere.

NASA said Tuesday, “the site is on ‘Murray Ridge’ – a section of the rim of Endeavour Crater where Opportunity is working on north-facing slopes during the rover’s sixth Martian winter.”

Currently two theories have arisen as to where the new rock may have come from.

The first idea put forward by scientists is that the rover itself may have dislodged the rock with its wheels while driving around. Additionally, the white coloration could be a result of the wheels flipping the rock over and exposing the underside.

The new mystery rock has been named ‘Pinnacle Island’ and has excited scientists working on the mission.

In a statement on Tuesday, NASA said, “much of the rock is bright-toned, nearly white. A portion is deep red in color. Pinnacle Island may have been flipped upside-down when a wheel dislodged it, providing an unusual circumstance for examining the underside of a Martian rock.”

This before-and-after pair of images of the same patch of ground in front of NASA's Mars Exploration Rover Opportunity 13 days apart documents the arrival of a bright rock onto the scene. (NASA/JPL)

This before-and-after pair of images of the same patch of ground in front of NASA’s Mars Exploration Rover Opportunity 13 days apart documents the arrival of a bright rock onto the scene. (NASA/JPL)

All the other rocks in the area appear the more typical Mars reddish-brown.

The second theory is that a meteorite may have impacted the surface somewhere nearby and this rock, which does look unlike other rocks in the area. The new mystery rock could be a small fragment of the meteorite.

The first image of the area was taken on December 26, 2013 on Sol 3528. The second image was taken on January 8, 2014 on Sol 3540.

A ‘Sol’ refers to a Martian day, which is 40 minutes longer than an Earth-day.

The Sol reference number explains the number of days since Opportunity landed on Mars a decade ago – on January 25, 2004.

Opportunity has far exceeded its original mission, which was set to last for 90 days. (there are some festivities planned for later in the week the celebrate the anniversary)

The images for this mystery were taken using Opportunity’s panoramic camera, or ‘Pancam’.

If either theory is true about where this rock came from, what a great opportunity (pardon the pun) for science!

Isn’t it great that we have robots out there to investigate things like this?

Though the flip side: imagine how much we must be missing because space is very dynamic and we only have a few robots out there watching.

(A newsy version of this article also appears on Sun News Network)

As we sail into the unknown

13 Sep

This is a big moment in human history, though like many moments it probably won’t sink in for years to come. Nevertheless, humanity – with the reach of the incredibly long-lived Voyager 1 space probe – is now a civilization of the stars.

The official announcement came from NASA yesterday (September 12, 2013) after careful data analysis from Voyager 1’s Plasma Wave instrument: the spacecraft has passed though the heliopause (the bubble that separates the inside of our solar system from the outside) into the interstellar medium.

To watch the full press conference, hit play here:

NASA scientists were able to confirm Voyager 1’s exit from the heliopause by measuring a significant change in the plasma density that surrounds the probe. And interestingly, the change they noted was a marked increase in density. This may seem counter-intuitive, but as the plasma temperature of the interstellar medium is significantly cooler than the solar system’s plasma, the increased density makes sense – and was in fact expected.

(Warning, the following is a simplification: All things being equal, cool objects have a higher density than warm objects, as their molecules have less energy and pack closer together. This is why solids are denser that liquids; liquids denser than gases; gases denser than plasma – in each state of matter transition energy is added, which causes a decrease in density.)

“Exploration is in our nature. We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars.” ― Carl Sagan

The other interesting thing to note is that Voyager 1 , it appears, actually entered interstellar space on August 25, 2012 – more than a year ago! But it took until now to make sense of the data the probe was sending back. But I kind of like this. When we as a species are going somewhere and doing something no one has ever done before, it takes time for us to understand what we’re seeing and what’s happening. Exploration and discovery doesn’t happen in 20 seconds – it takes years (and historically speaking, many years) of concerted human effort to accomplish these amazing firsts – whether we’re talking about crossing the oceans, inventing medicines, sailing around the globe, building landmarks, landing on the moon, and now leaving the solar system.*

Voyager 1 is right now about 19 billion kilometers from the Earth, or 125 times further from the Sun than we are, and getting ever further away at a speed of about 60,000 kilometers per hour – or roughly 500 million km per year! A little perspective: we think of the dwarf planet Pluto as “far away” but Voyager 1 passed the orbit of Pluto in 1989 – 24 years ago!

And let’s not forget about Voyager 2 either. It is still within the heliopause, and will also cross into interstellar space in the coming years. Voyager 2 is on a different – slower – trajectory than Voyager 1 and so it is about 5 billion kilometers behind its twin sister, on a southbound course away from the Sun.

The Voyager mission will, I expect, to continue to deliver more discoveries. As the probe continues to sail into the unknown I look forward to it sending back new data that will continue to answer questions – and perhaps more importantly – raise new questions, in order to push our understanding of the universe forwards.

To read more about the Voyager mission, check out these other posts I’ve written on the subject over the last couple years.

* While Voyager 1 is now travelling through interstellar space, it technically hasn’t left the solar system. I know this might sound bizarre, but it’s due to the fact that the Sun’s gravitational influence reaches far beyond the influence of its plasma. There are (at minimum) billions of chunks of rock and ice in the Oort Cloud that orbit our Sun over thousands of years that are still many times further away from the Sun than Voyager 1 is. It may be in fact thousands of years before Voyager 1 passes the last of the Oort Cloud objects. All that having been said, the heliopause is accepted as the limit between inside our solar system and “amongst the stars” in interstellar space, just as Oort Cloud objects are “among the stars” even while being bound by gravity to our Sun. Phil Plait also wrote on this subject here.