Philip P. Ide

Author, programmer, science enthusiast, half-wit.
Life is sweet. Have you tasted it lately?

User Tools

Site Tools


blog:aardvaark:mars_weather:start

Mars Weather

Weather Reports
Insight Lander
Perseverance Rover
Curiosity data to come

Follow Conjunctionsplugin-autotooltip__default plugin-autotooltip_bigMars Solar Conjunction

This page is currently INACTIVE for 2021 conjunction

Mars is heading for a solar conjunction, which in layman's terms means it's on the opposite side of the sun from the Earth. For a short period, no commands will be sent to the Mars spacecraft (which includes landers and rovers) since the sun's corona could corrupt those commands and result in unintended actions, disablement of the spacecraft or worse.
as they occur.

Locations of Mars Landers. NSYT=Insight, M20=Perseverance, MSL=Curiosity

Martian Day

The Martian day is 39 mins 35.244 secs longer than a standard day. This means that approx every 36.1 days the Earth weather date skips a day while the Martian Sol marches on as normal. You can see this in the Insight data. April 16th 2019 seems to be missing, yet the Sols on April 15th and April 17th are consecutive.

Current Time on Mars

The Martian day - or sol - is 24hrs 39mins 35secs long. For convenience, Martian clocks keep a 24hr time, requiring the Martian second to be a little longer than it is on Earth (approx 1.0275 secs).

These clocks reflect the local times at the prime meridian, InSight's location, Curiosity's location and Persevance's location and keep Martian time (using its extended seconds). InSight was intended to land at 135.974°E, but actually landed at 135.6234°E. The InSight Clock uses the actual landing site, while the Mission Clock (used by the mission team) uses the intended landing site. As Curiosity and Perseverance are Rovers, and their exact positions cannot be determined, a fixed position within the craters are used and reflect the mission clocks used by the mission teams.

LS is the solar longitude - the angular position of the planet from the vernal equinox - and is important in many equations, particularly regarding time and dates. The value displayed here differs from that at James Tauber's Mars Clock, which itself differs from the value displayed by Mars24. I had to choose one of them as my benchmark, and since I use Mars24 as the benchmark for the clocks, it seemed reasonable to choose Mars24 to remain consistent. The difference between the two (Mars24 and Tauber's algorithm) is only 0.00628° anyway, but otherwise they are in lock-step.

Although LS effectively describes the planet's position in its orbit around the sun, it is actually a function of time on the planetary analemma, since it describes the position on the analemma for a certain date and time.

MSD is the Martian equivalent of a Julian date, and this refers to the number of sols since Dec 29th 1873. For obvious reasons, this keeps Martian time. Note: if you use the Mars24 program, you may note the MSD displayed in that program differs slightly from this one. It seems Mars24 rounds the numbers, so when MSD reaches a 0.005 precision boundary, it rounds up. It doesn't seem to do this for MJD.

MJD is the Modified Julian Date. This ignores the first 2,400,000 days in the standard Julian date, and moves the starting point to midnight (from midday). This is further modified to reflect the coordinated universal time for spacecraft, which is some 5hrs 45m adrift of UTC.

Since MSD uses Martian time and MJD uses universal time, you'll see them slide in and out of synchronicity.

There are several Martian Calendars in use. NASA uses MSD, but the year/month calculations in the above clocks use the calendar proposed by R. Todd Clancy (Clancy et al., Journal of Geophys. Res 105, p 9553, 2000), whereby the Calendar begins at midnight on the morning of April 11th 1955 (when Ls = 0) and with the first year being year 1.

Martian years are approx. 686 Earth days long, equating to roughly 668 sols. Sols are counted from the start of the year because of the huge variance in the length of Martian months, which vary in duration from 46 to 67 sols.

Martian months are calculated based on the number of degrees Mars is around its orbit (each month being 30°). This means most months end partway through the day. In order to ensure a month consists of whole days, the calculation employed here rounds down to the nearest whole number. Therefore, if the end of the month occurs on sol 68.2, all of sol 68 occurs in the last day of the month. This is a convenience, and there is no formal convention on how to handle this. Other calculators may begin a month on any day where the month begins, so in the above example, sol 68 may be the first sol in the new month.

If you are wondering why the sols on the clocks don't match the sols in the weather reports, the weather reports refer to mission time, rather than the start of the Martian year. Besides being a convenient way to track mission duration, it guarantees two data points in different years have unique sol counts.

Current Location of Mars

no data

no data

no data

[1] the calculation is based on data from the Planetary Society, and divides the Martian year using the equinoxes and solstices. Further, it uses UTC to perform the calculations rather than Airy Mean Time (AMT), so is only an approximation to provide a rough guide. AMT is the Martian equivalent of GMT. The Martian year is 686.97 standard days (668.6 sols), approximately 1.88 years.

[2] Calculation is based on data from Goddard Institute for Space Studies

[3] Calculation is based on data from Goddard Institute for Space Studies and other sources

Current positions of Earth and Mars Image courtesy of https://in-the-sky.org and © Dominic Ford

This image is updated once per week. A daily update is available on the Mars Solar Conjunctionsplugin-autotooltip__default plugin-autotooltip_bigMars Solar Conjunction

This page is currently INACTIVE for 2021 conjunction

Mars is heading for a solar conjunction, which in layman's terms means it's on the opposite side of the sun from the Earth. For a short period, no commands will be sent to the Mars spacecraft (which includes landers and rovers) since the sun's corona could corrupt those commands and result in unintended actions, disablement of the spacecraft or worse.
page when such events are active.

You can check the position of Mars vs the Sun and Earth for any date here: https://in-the-sky.org/solarsystem.php?obj=P4

See Also

Orbital Shenanigansplugin-autotooltip__default plugin-autotooltip_bigOrbital Shenanigans

[MOLA map of Mars coloured by elevation]

Edited: 2019-03-14

Sometimes when you do some research – actually, quite often – you find out some really interesting stuff and end up changing your mind. In my story, I had some people on the ground on Mars, and wanted a spacecraft in a geostationary orbit above them to give them communications between them at all times. Just for info, when talking about geostationary orbits, the accepted term for Mars is aerostationary. I’ll use g…
| Mars Solar Conjunctionsplugin-autotooltip__default plugin-autotooltip_bigMars Solar Conjunction

This page is currently INACTIVE for 2021 conjunction

Mars is heading for a solar conjunction, which in layman's terms means it's on the opposite side of the sun from the Earth. For a short period, no commands will be sent to the Mars spacecraft (which includes landers and rovers) since the sun's corona could corrupt those commands and result in unintended actions, disablement of the spacecraft or worse.
| Perseverance Roverplugin-autotooltip__default plugin-autotooltip_bigPerseverance Rover

Perseverance has launched succesfully and the clock is now counting flight and ETA time. It is due to land on Mars on (times and countdown timer based on NASA's timer):

* Feb 18th 2021. * * * * * * *

This website uses cookies. By using the website, you agree with storing cookies on your computer. Also you acknowledge that you have read and understand our Privacy Policy. If you do not agree leave the website.More information about cookies

Discussion

Enter your comment:
A O J​ Y K
 
blog/aardvaark/mars_weather/start.txt · Last modified: 2022/09/12 11:04 by Phil Ide

Except where otherwise noted, content on this wiki is licensed under the following license: Copyright © Phil Ide
Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki
  • ISSplugin-autotooltip__default plugin-autotooltip_bigInternational Space Station

    This page has a portal through which you can view the current location of the International Space Station, updating in real-time. The tracker itself comes from the European Space Agency (ESA).

    There is also a handy link to get email notifications direct from NASA when the ISS is visible in your night sky.
  • Mars Weatherplugin-autotooltip__default plugin-autotooltip_bigMars Weather

    Weather Reports Insight Lander Perseverance Rover Curiosity data to come Follow Conjunctions as they occur.

    Martian Day

    The Martian day is 39 mins 35.244 secs longer than a standard day. This means that approx every 36.1 days the Earth weather date skips a day while the Martian Sol marches on as normal. You can see this in the Insight data. April 16th 2019 seems to be missing, yet the Sols on April 15th and April 17th are consecutive.
  • Downloadsplugin-autotooltip__default plugin-autotooltip_bigDownloads

    Orbital Calculator Current Version This is a portable application, meaning there is no installer. Just unzip into a folder and run the executable. Since it is portable, it can be run from a USB stick.

    A full description and a list of the features are available
  • Orbital Calculatorplugin-autotooltip__default plugin-autotooltip_bigOrbital Calculator

    I needed to calculate orbital characteristics for any orbit around any gravitational mass (because I write sci-fi stories), so I wrote this program because I'm a programmer and I'm too lazy to do it by hand all the time. The program has expanded over the last few years, sometimes from suggestions by other writers. I make it freely available and as simple to use as possible. It now has a list of functions as long as your arm (assuming you're not a tentacle user), and the numbe…
  • Cookie Policy & GDPRplugin-autotooltip__default plugin-autotooltip_bigCookie Policy & GDPR

    There are NO tracking cookies on this site!

    The Cookie policy is straightforward. This site only uses cookies that are required to make your experience of using this site better, and only uses session cookies (see exceptions below). Session cookies are deleted when you close your browser.
  • Book Reviewsplugin-autotooltip__default plugin-autotooltip_bigBook Reviews

    Here you can find all the book reviews, broken down by genre, and further subdivided by author. If you want me to review your novel, please read my Rules on Reviewing.

    * Science-Fiction * Fantasy * Non-Fiction
  • Contactplugin-autotooltip__default plugin-autotooltip_bigContact

    If you have a burning desire to contact me, use the discussion form below. Anything you say remains private between you and me.