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Space exploration writer ✨ Contributing Editor for The Planetary Society ✨ Moon evangelist 🌗

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12 years ago today, India’s Chandrayaan 1 spacecraft captured a solar eclipse from the Moon! I made this GIF from its images.

Details of execution in my interview of Chandrayaan 1’s Mission Director:… 🚀

My Dad wrote this on the board today. Above is Neil Armstrong’s “One Small Step..” quote in Gujarati.

I assure you I had little role getting him excited for today’s Blue Origin launch of humans. Say what you want about commercial space, it does get people excited in new ways. 🚀

Last week in Moon exploration saw hardware progress! 🌗

→ NASA readies Orion for 1st flight around the Moon

→ ispace Japan begins assembling its lunar lander

→ China distributes Chang’e 5 samples for scientific study

→ Astrobotic advances its autonomous rover

and more! 🚀

When India’s Chandrayaan 1 found water on the Moon, it changed the course of global lunar exploration. Here’s the story of its discovery that spans 2 decades and across multiple space agencies:… 🌗🧊

Or why you should get a website and domain name.

A friend recently told me, “(Her) Blog feels like home.”

I couldn’t agree more.

That led me to think of analogies for social platforms and websites in terms of how much power and freedom they actually give you over your content. If we think of your content on the internet in terms of physical places, this is what they are like.

  • Social platforms like Twitter, Instagram, LinkedIn, YouTube → Hotel rooms
  • Free Blog or Website → Rented house
  • Website/Blog + Domain → Home

If you’re serious about what you write, create, or put out on the Internet, get a domain…

On our celestial companion’s immense scientific and exploration value.

Many people think that the Moon is just a gray ball of rock in the sky. Surprisingly, many scientists share this notion too. I once had a physicist tell me the Moon is boring. So I’m writing this article to summarize the immense scientific and exploration value of our Moon.

View of the Moon by the Galileo spacecraft as it flew by it on December 7, 1992. Credit: NASA

Why do we explore the Moon?

The bootprints of Apollo astronauts who walked on the Moon are still there. That’s because the Moon is airless and so things stay unchanged for years. This single fact makes the Moon a geological time capsule.

The black hole’s spin rate also turned out to be close to the theoretical maximum. Beyond that limit, black holes lose their event horizons.

An artist’s illustration of a black surrounded by an accretion disk, as in the discovery of 4U 1630–47. Credit: NASA/JPL-Caltech
This article was originally published for The Wire. This is a mirror of the same.

ISRO’s first space telescope, AstroSat, and NASA’s Chandra X-ray observatory, also space-based, have together found a black hole that spins at a rate close to the theoretical maximum. Designated 4U 1630–47, the black hole weighs about 10 solar masses — a stellar mass black hole, not one of the gigantic ones found at the centers of most galaxies.

Stellar mass black holes are formed when a giant star collapses under its own gravity, The entire mass is crushed to a single point called the singularity…

How the Apollo missions transformed our understanding of the Moon’s origin

This article was originally published on The Planetary Society as a contribution for the Apollo 11 landing anniversary. This is a mirror of the same.

Where did the Moon come from? The origin of our cosmic neighbor is a fundamental question in planetary science. From Galileo’s first telescopic observations of the Moon to humans walking on its surface, our understanding of its origins has come a long way. Yet it is far from complete.

There are multiple hypotheses that have attempted to explain how the Moon came to be. …

Designing lunar orbits to efficiently land on the Moon

The TeamIndus spacecraft will soft-land on the Moon in 2020. The landing site for this first mission (Z-01) is near Annegrit crater, in the vast lava plains of Mare Imbrium.

TeamIndus Z-01 spacecraft landing site: Near Annegrit crater, in the vast lava plains of Mare Imbrium. Source: LROC Quickmap

The location of the landing site poses multiple constraints on how the spacecraft orbits are designed, including the launch/landing time and everything in between. Let’s take a look at the constraints imposed by the landing site first, followed by the nature of the lunar orbits.

Part A: Constraints on lunar orbits

1. Sun illumination

A lunar day is equivalent to 14 Earth days (between 70 N/S) and we want to maximize the surface operations time post-landing. Landing at local…

Jatan Mehta

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