Inspired by Lord Alfred Tennyson’s Locksley Hall, on Planet Four Talk Pete (p.titchin) reflected on the arrival of Martian Southern Spring. We thought it was lovely and wanted to share with all of you. Thanks Pete:
In the Spring, the sunrise heralds changes on the Martian ice: In the Spring, a P4 classifier’s fancy lightly turns to thoughts of —-SUBLIMATION!.
Add your own verses in the comments or on Talk.
I’ve been learning to use JMARS (Java Mission-planning and Analysis for Remote Sensing) to plot the coverage of the CTX images for Planet Four: Terrains. JMARS is a really nice tool for overlaying observation footprints and different maps and datasets on top of each other for Mars and other planets.
I decided to take a look at what the HiRISE Season 2 and Season 3 observations, that the science team is currently working on writing up, look like on a map of the South Pole when you plot their physical coverage on the pole . You can really see the overlap and what a small area that HiRISE covers compared to CTX.
Here’s the footprint HiRISE observations for Seasons 2 and 3 outlined in red on the elevation and topography map of the Martian south pole (latitude and longitude lines are in 10 degree intervals).
Here’s a zoom in on one of our favorite regions, Inca City. You can really see the repeat coverage outlined in white in this case.
Here’s another zoom in of a different area, where you can see multiple seasonal targets outlined in red:
For comparison here’s the footprints of the first set CTX images (latitude and longitude lines are in 10 degree intervals). The colors represent geologic units, but for this comparison we’re focusing on spatial distribution and coverage.
WeMartians is a brand new podcast aimed to engage the public in the exploration of Mars. The latest episode is about citizen science on Mars with Michael talking about Planet Four and Planet Four: Terrains. Listen to Michael (and cameos of other familiar Zooniverse voices) below or on the WeMartians website.
Yesterday marked a decade since Mars Reconnaissance Orbiter (MRO) went into orbit around the Red Planet. A few months later science observations commenced, and since then the mission has been studying the Martian surface and atmosphere. We use MRO data on both Planet Four (HiRISE [HIgh Resolution Imaging Science Experiment] images) and Planet Four: Terrains (Context Camera [CTX] images). Thanks to the contributions of those at NASA and the instrument teams (including engineers, scientists, software programmers, and other operations support team members) who make these observations happen and keep the spacecraft and its suite of instruments happy and healthy.
With 10 Earth years (or ~5 Mars years) of observations, we can look for long term changes in the geyser formation process, and this summer we’ll be pointing HiRISE to new regions of the South Pole thanks to the contributions from Planet Four: Terrains volunteers for monitoring for several more Mars years.
Below is a highlight reel compiled by NASA of MRO’s greatest science hits and images over the last decade.
There have been so many iconic moments from the MRO’s mission, but I think two moments are HIRISE capturing the descent stage of the the Curiosity rover with the parachute and the parachute of the Phoenix lander several years before.
Wake up early and view our planetary neighbors in all their glory. Starting this weekend you’ll be able to find Mars and four other planets from our Solar System visible in the early morning sky. In addition to the Red Planet, this planetary alignment includes Mercury, Venus, Jupiter, and Saturn. Some of the planets will continue be visible for over two or three weeks, but the best time to see all five is from Saturday, January 23 through the first week of February.
Below is a guide to help direct you to the right spot. Just before dawn (about 45 minutes before) while the sky is is still dark will be the best time to look.
Most of the planets are bright compared to stars in the sky so you should be able to glimpse them without the need of a telescope or binoculars, though you’ll likely need binoculars to spot tiny Mercury. If you’re having trouble identifying the planets from the backgrounds stars in the patch of sky, this (below) might help.
Mars should stand out as it will have a reddish tint thanks to all the iron oxide dust (or maybe better to say rusty dust) that covers it surface and swirls in its atmosphere. The bright star Spica will be in the middle between Jupiter and Mars, but our own Moon will also join this cosmic display, so if you’re having a hard time finding the planets, then try on the morning around February 1st. That’s when our Moon will be visible near Mars.
You can find more details on how to spot this early morning show here and here. If you do spot Mars, take a moment to think about the fact that you’re viewing a world that you can help better understand how the atmosphere/climate of this distant world works. You can explore Mars and help map seasonal fans on the South Pole of Mars with the Zooniverse’s Planet Four project ( http://www.planetfour.org), and if you do get a glimpse of Mars, post your photos in the comments section and we’ll post them here in a future blog post.
Thanks to Talk moderator Andy (wassock), we have a handy map that overlays previous plots I’ve made of the locations of the HiRISE images being focused on by Planet Four and the CTX images that are being searched on Planet Four: Terrains. He’s also marked some of the target of interest areas like Ithaca, Inca City, Manhattan, and Giza that we’ve been trying to focus on over the past two years on Planet Four.
Andy overlays the plot on top of the geologic map of the Martian South Pole produced by the United States Geological Survey that’s been discussed on Planet Four: Terrains Talk. You can find more details about it here.
You might have seen an image like the one above while classifying on Planet Four: Terrains. It reminds me of Jackson Pollock’s painting style. Those dark lines crisscrossing the image are actually dust devil tracks. Dust devils are mini-tornadoes on the surface of Mars, kicking up and clearing dust in their paths. Dust devils exist in the plains and deserts on Earth. The Martian equivalent can be considerably bigger than those found on Earth. Their tracks can be seen from orbit in images from CTX and other cameras.
Here’s what dust devils look like from orbit. This image was captured by the HiRISE camera on Mars Reconnaissance Orbiter.
Dust devils have been caught in the act on the ground in the mid-latitudes by several robotic rovers and landers including the Mars Exploration Rovers (Opportunity and Spirit). Actually Spirit and Opportunity have had dust devils pass over them, cleaning their solar panels. Below was a series of dust devils passing through nearby the Spirit rover in Gusev crater.
You might be wondering why we don’t ask you to mark these in the main Planet Four: Terrains interface. The reason is because they’re so ubiquitous that a full map of their locations isn’t needed, but if you’re interested you can identify images like this on Talk using the #dustdeviltracks hashtag.
Thanks to volunteer o0ohando0o for spotting this image and posting about it on Planet Four: Terrains Talk. You can find more examples of dust devil tracks as well as other things you might encounter in the Planet Four: Terrains images in our Site Guide.
I stumbled upon a week or so ago across these past images of Inca City captured by various NASA spacecraft on the NASA Space Science Data Coordinated Archive’s Mars Photogallery, and I thought I would share.
As you know the HiRISE team has unofficial nicknames for many of the regions that are monitored with HiRISE for the South Pole Seasonal Processes. Some of these you’re familiar with: ‘Inca City’, ‘Manhattan’, ‘Giza’, etc, but Inca City’s nickname comes from actually the days of the Mariner missions.
Mariner 9 imaged the Inca City area in the 1970s, and the story supposedly goes that the geographic features reminded the science team of a fallen or buried city and the moniker has stuck up until present.
I talked the other day about the modern day views of Inca City, but here are some taken over time. It’s amazing to see how our view of this region has sharpened and come into focus.
Inca City if you recall is one the regions concentrated with boulders as seen in the HiRISE images, but if you zoom out you like in the Mariner 9 image you can see honeycomb features that are interconnecting rectilinear ridges. How exactly this formed was not fully known, but with the Mars Global Surveyor (MGS) has shed some light on the regions origin.
Mars Orbiter Camera aboard MGS sees for the first time that Inca City is associated with a larger circular feature. One prevailing theory is that larger structure is a impact crater that has been buried or filled in and partly exhumed. Even if it an impact crater, there are several proposed mechanisms resulting from this situation that could produce the geographic features in Inca City. If it is an impact origin than very like the boulders you’ve seen in the images reviewed on Planet Four that are spread across Inca City are impact derived.
We see high resolution non-map projected color mosaic images of the Martian South Pole from HiRISE, but with the Context Camera (On Planet Four: Terrains we show the diced up CTX images), you can get a wide view perspective. This is the main drive of Planet Four: Terrains, to use the wide-field Context Camera (CTX) images to find new areas of interest that we can then explore and study in detail.
On the original Planet Four, we’ve spent a lot of time over the past two years focusing on the region informally known as ‘Inca City.’ With CTX can you can get a bird’s eye view of Inca City and its structure. Check out the image below. You’ll notice the unique pattern of interconnecting rectilinear ridges that the region is known for.
You can view the full resolution version of this image here
Today we have a guest post Dr. Nicholas G. Heavens. He is a Research Assistant Professor of Planetary Science at Hampton University in Hampton, Virginia. He studies the weather of present day Mars, the climate of late Paleozoic Earth, and the atmospheric evolution of Earth-like planets outside the Solar System. He is a member of the Mars Climate Sounder science team.
Dear Explorers of the Fourth Planet,
Chances are, at some point, you have found yourself by a still body of water on a rainy day. Entranced by the smooth surface of this lake or pond, you began to feel the rain fall on your head and shoulders. And as the rain fell on the water, you noticed circular ripples radiating out from each raindrop and moving toward the shore.
Those ripples are a particularly beautiful and elegant example of a type of wave known as a gravity wave (or sometimes buoyancy wave). The raindrop’s impact depresses the surface of the water, upsetting the balance between the force of gravity and the pressure exerted by the water. Water then moves into the hole to restore this balance, creating a further imbalance that spreads the energy of the impact (but not the water itself) outward as circular rings.
Gravity waves in water are a familiar sight in our everyday lives, but gravity waves are common in atmospheres as well, including Mars’s. On average, gravity and air pressure in Mars’s atmosphere are in balance, meaning that less dense air is higher in the atmosphere than more dense air. However, in some situations, denser air can be forced over less dense air, resulting in gravity waves that can propagate to higher altitudes and grow in amplitude as they do so. Some of those waves can be quite inconvenient, since they make up much of aircraft turbulence.
When you look at Planet Four images, you stare at high-resolution, mostly cloudless images of Mars near its poles. What I want to show you today is what might be happening in the atmosphere above, as seen in cloudy, low-resolution images of Mars. It is common to see visible indications of gravity waves in the winter hemisphere around 45 degrees south, but gravity waves are likely active at other times and places.
In the first image, do you see circular, whitish ripples near the center of the image? Something analogous to raindrops dropping in a pond has happened there. In the parts of the waves that correspond to rising air, water vapor is cooled and condenses into ice to clouds that trace out the waves.
In the second image, the wave fronts are not strongly curved and appear to be radiating in one direction, probably indicating that a strong wind is affecting the waves. In each case, the wavelength of the waves can be easily measured, around 40 km in the first case and around 20 km in the second case. The source of the first set of waves is unclear (at least to me). The source of the second set of waves is probably the interaction of dense cold air from the pole moving over less dense warmer air at lower latitudes. In some images, the source of the waves can be traced to wind dropping down into a crater.
Studying gravity waves can tell us much about how Mars’s atmosphere works from bottom to top. Future Martian glider pilots also might appreciate knowing when they occur and the conditions they will create. But I will admit that my interest in Mars’s atmospheric gravity waves continues to be fed by the disturbing beauty they bring to Mars’s thin atmosphere.