Category: Astronomy

Mars Mission Decoded To A Four Year Old

Vasvi declared that she wanted to go to Mars, and I had to decode a lot of things for her to explain the differences between San Francisco and where she wants to go. The best way to overcome challenges is to face them and start thinking about how this generation needs to prepare.

Feature Simple Speak
Gravity (3.71 m/s2) You’ll walk as if you’re light-hopping, you’ll weigh only 1/3rd; Jumping from a rock will feel slow motion (you’ll take about thrice as more time to fall)
Diameter (6794 km) Will take half the time to get around Mars, map scales will be larger
Sun’s luminosity (40%) Brightest days will look like very early mornings
Atmospheric Pressure (600 Pa) Water will boil at about 0 degrees C, right where it freezes here on Earth (see this table)
Temperature (-60C) Really cold as compared to most of earth
Two Moons As fascinating as this sounds, these are really very small rocks around Mars, as compared to our moon and have minimal effect on Mars. In reality, you can’t see a large moon on Mars (its pretty empty).
Orbital Period (687 Days) Summers will last about 6 months, and every other season will be longer than here. Calendars will have longer months and longer years there.
Life (unknown) There are no trees, no bees, no butterflies, no birds and no flowers. Its pretty empty from a living creature perspective.

To a child’s mind, the differences are not as extraordinary as it is to adults. They are still linking to what is supposedly normal.

Getting There

It was not funny for me any more after Vasvi repeated that she is going to Mars, and will on the way stop on Moon and Venus. I asked her what challenges will she have to overcome to get there. She had no idea. I decided to document some challenges in simple speak for a Vasvian brain.

What Simple Speak
Distance (60 to 400 million km) Mars and earth are constantly moving around. It would be best to start when Mars is closer to Earth. If I call you when you’re around Mars, my “hello” will take anywhere between 5 and 20 minutes to reach you. It is that far.
Launch Window About every two years, Mars and Earth are somewhere close that it will be fastest to get there. Our next launch window is Mar/2016. (cosmic schedule)
Packing Food, water, recycle gadgets (to convert gases and liquids back to being usable), space suits, solar panels/batteries, a telephone, an exercise machine and your favorite Alouette..
Delta-v Budget How much money we will spend? This will depend on how much “gas” (propellent) is required, and how fast we can go. We’ll have to use the gravity (or the pull force) of other planetary bodies to gain speed (gravity assist), helping reduce the money we have to spend.
Spacecarft A big giant car, with lots of buttons inside. This is where you will live for about 7-8 months, so it should be nice inside.
Radiation Like very bright sunlight bothers, there are other types of “lights” that are dangerous and can be harmful. Sunscreen lotions can’t protect, so your spacecraft will need to have special outer coatings to protect from this radiation. Otherwise, it can be similar to you being inside a microwave
On the way It will be dark outside, and the sun would be suddenly very bright. Lots of stars to see, the moon will show itself on the way, and depending on when the launch date, Venus could be seen from close enough. Earth will look like a blue ball, that gets smaller and smaller, every time there’s actually a chance to see it. Lots of exercise will be needed on the way so that bones and muscles stay strong.
Mars Orbit Go around Mars, round and round, instead of landing down. Mars’ air and atmosphere will help a slow down to stay above it. Going around the planet, mornings and nighs may be shorter – ranging from a few to many many hours of day and night. Going around will be strange, since it will be elliptical – very close and then very far. Two not so big rocks will be seen, one very close (Phobos) to Mars and another one further away (Deimos). Earth won’t be seen as it used to be seen. 

Landing

At this time, exhausted with the information overload, the decision was not to land on this trip. We’ll land some other time, time to come back.

Coming Back

This is another complex task that I couldn’t get any reliable data for, at least as of this writing. Challenges of coming back had to be simple-spoken.

Homeward Simple Speak
Distance (60 to 400 million km) The same distance needs to be covered as earlier. At best, the journey can start only about a year after it was accomplished, since launch windows occur every two years, remember?
Launch Window The next launch window from Mars will be in Feb/2018 – about 15 months after reaching there. This will mean a lot of waiting while going around the planet.
What to pack Just eat very slowly, don’t waste any chocolate bars and keep calm.
Delta-v Budget Significantly higher amount of money is needed to pack double the fuel for getting back (to achieve the same speeds). Multiply everything you want to get there by 2. This may not be completely true if you are above Mars.
Spacecraft Much bigger spacecraft, since you will be taller and supposedly heavier, you need more playground. This increases the delta-v budget, meaning more money.
Psychological Impact Again, it will be very dark outside. Time will seem like it will never end. Feelings of “no one cares” will develop. Alouette, of everyone else, may suddenly seem like the only one who cares and loves. This will be hard.
Close to Blue Being back on Earth doesn’t look any further. Sitting in a space capsule to fall into an ocean sounds easy, but an additional space capsule in the craft is needed. More delta-v. Alternatively, achieve a low earth orbit and then someone comes to pick up. Super-alternatively, somehow attach to the International Space Station – though no one would like the possibility of destroying a $100 billion thing if something went wrong.

Will we get there?

This was the big question. After all this explaining over a few days, this question always rang with a super-optimistic spin at the end – “Yes?” I am just as optimistic as the little one. Yes, we’ll get there, and possibly, some would make it back.

Red Moon During Lunar Eclipse

This Moon (Lunar Eclipse)is a photograph (credits to Hemant Hariyani) taken during a lunar eclipse. Besides being a very beautiful sight, there’s a curious orange tinge on the lower left quadrant of the moon. My curiosity lead to the moonzoo (please search for the terms “blood red” on that page to see their reason) – which explains very briefly the cause of this. While discussing on a list, I realized that it’s confusing sometimes to visualize how exactly this happens – so I drew a diagram to get this straightened out.

Reason for the moon's blood red (orange) color during lunar eclipseRefraction causes light to bend – and when different colors of white light bend at different angles, that causes light to split up; the very cause of rainbows. This is enough theory, the rest is self explanatory in the diagram beside this text. As you can figure out, light from the sun, reflected refracted when passing through earth’s atmosphere – falls on the moon (and since only longer λ [red] reach out) it looks orange (or blood red).

It’s imperative to note, that the cause of this blood red color is very different from the cause of the blood red color we see when the moon rises on certain nights. That blood red is caused because the light coming from the moon gets scattered when passing through the earth’s atmosphere (more so, polluted atmosphere), which causes the red waves to fall on our eyes and make the moon look red. That is when the light from the sun gets reflected back on earth and on it’s way to our eyes, we see red (the whole thing looks red – unlike this phenomenon).

Dhanushkodi: Annular Eclipse

Moon's shadow on EarthWas my first time at an annular eclipse (with 100% contact – have been in partial contact once in 2005). Just to be clear, an annular eclipse, contrary to a total eclipse, does not induce darkness due to the increased distance of the moon from the earth. To understand further, you might want to see this image (preview on the right).

Pavan (an active volunteer of BAS) was accompanying me and Raghu on this trip. We drove to Dhanushkodi via Madurai and Rameshwaram (the oncoming two/three wheelers on your side of the lane deserves a separate post). We almost got killed by an oncoming Ambulance. A day’s stop in Madurai on Jan 14 and Jan 15th saw us in Dhanushkodi (DKD). DKD is right across Pamban bridge, some 10 Kms from Rameswaram. It’s a small island, surrounded by the ocean on two sides and extends to the last point of India that just touches Sri Lanka.

Annular Eclipse Phases - (click to view larger: in a new window/tab)

Contrary to expectations, DKD was free of an enormous crowd. The Tamil Nadu Science Society was organizing an event there (and quite a few folks from Assam – the Guwahati Planetarium, Gujarat, Bengal etc. were to be seen). Photos were being clicked as the “Media” approached us and we shyed away. Though we were carrying a telescope, due to lack of a filter we could not set it up and missed  the oppurtunity to use it. Pavan got a filter for his camera right on time (though I carved out something with an X-ray sheet, but the mylar sheet filter was definitely a better bet).

First contact of the eclipse was at 11:15 AM – as we put on our eclipse viewers, the sight was stunning.  The intensity of the sunlight decreased by as much as 75% (approximately) and the temperature certainly decreased by at least a couple of degrees (if not more). The sea wasn’t very rough, but the tide certainly had increased a lot more than what it was in the morning.

At about 1:20pm, we saw the ring – a beautiful sight as I kept gazing at it. There’s still a lot of light around you, just that it is white and not the usual yellow light and the intensity is nothing like a sun in a clear sky. The sky was spotless during the maximum eclipse around the sun, but it felt like there’s a cloud covering. Something very unusual, but a characteristic property of an annular eclipse on the ground. To understand how the eclipse traces the path on the ground, see this image.

We came back to Rameshwaram, stayed on till night and hopped back home the next day.

Interestingly, Raghu pointed out that I ended up following the popular superstitous Hindu activity of:

  1. not eating anything during the eclipse (though I drank some water and ate peanuts – which he discounts as: “even monkeys eat them“),
  2. taking a bath post-eclipse (we found a room at Rameswaram only in the evening, so I took a bath ASAP),
  3. visiting a temple post-eclipse (we went to hog – but couldn’t find anything since Rameswaram halts between 5pm and 6.30pm – so we had to go into the temple to make the most of our time)
  4. eating only after a bath (we were forced to take another 22 baths in the Kunds in the Rameshwaram temple – and then we hogged Dosas).

Heh, I broke (1) though, while Raghu/Pavan somehow broke (1) and (2). So glad I am.