Podcast Space

Planetary Radio on Asteroid Bennu descent

Asteroid Bennu is slated for a close encounter with Earth in 2175. It is expected to be the asteroid that has the most chance for a possible Earth impact over the next 200 years. Hence, it was selected for NASA’s OSIRIS-REx mission.

Mat Kaplan at Planetary Radio sat down to discuss the mission with it’s Principal Investigator, Dante Lauretta. The mission is of interest because it will descent on Bennu’s surface in August 2020, collect a sample and return it to Earth in 2023. These are my podcast notes from that episode.

Lauretta talks about the mission updates till now. The spacecraft reached the asteroid and has been doing a series of mapping the surface of the asteroid. In December 2019, they selected the landing site, code-named Nightingale. All surface features on Bennu named so far are named after Egyptian birds. Bennu itself is named after an Egyptian mythological bird, that probably inspired the Greek bird, the phoenix.

The final four candidate OSIRIS-REx sample sites. Image Credit: Wikipedia

He then talked about the surprise of finding the surface of the asteroid so rocky. Apparently, radio and infrared studies of the asteroid’s surface had predicted the surface to be smooth. They had designed the instruments using the experience gained on the Hayabusa spacecraft which had a 25-meters radius for operations. They had given themselves a 50-meters radius for operations. But, the current landing site gives them just 5-meters. This means that they had to drop the LIDAR based landing navigation system and use a more optical based hazard avoidance system to land on the surface.

He then talked about cross-pollination between the Hayabusa and the OSIRIS mission with people working in each other’s projects. This is part of the on-going collaboration between NASA and JAXA.

They then spoke about some of the public outreach efforts of the mission. This is usually an integral part of all NASA missions. However, OSIRIS’ education and public outreach budget was cut in 2018. Lauretta then took it upon himself to continue the work. He designed board games and also supports Target Asteroids!, a program that takes help from amateur astronomers to observe certain asteroids. The board games include X-tronaut and Constellations.

Unrelated, but the episode ends with a session of Space Poetry.


Peak Planet podcast

Peak Planet podcast hosted by Karthik Ganesan. Image: IVM Podcasts

I listened to the Filter Koffee Podcast episode with Karthik Ganesan on my morning commute to work. I found the Peak Planet podcast on the IVM podcast network as a result. Contrary to Karthik Nagarajan’s usual episode, this felt all over the place. Rich in data but played out in starts and stops.

The notes here are from the Episode 2 of the Peak Planet podcast on data and a few notes from Episode 3. I binge-listened to all the episodes of the podcast after listening to the morning episode on The Filter Koffee Podcast. The podcast seems to have hit pause after 4 episodes that were out in November, 2019.

The first episode of the podcast introduced me to the Hinjewadi IT Park Residents Welfare Association (HIRWA). I loved their Twitter handle – HIRWA Hinjewadi. HIRWA in Marathi is Green and is usually associated with pollution-free advertisements along the lines of “Clean Mumbai, Green Mumbai” etc. So, this reads as “Green Hinjewadi” if you partly translate it.

The second episode is about data. Karthik G quotes Michael Bloomberg in the beginning, “In God we trust, everyone else please bring data.” The global standard in Air Quality Index measurements is to have 1 AQI reference monitor for every 1 million people. India has 1 per 7 million. And, most of these are concentrated in Delhi.

It is believed that air pollution is an urban phenomenon and this is not true. Sagnik Dey working out of IIT-Delhi says that we have no data on the background pollution level in India. Background pollution level is the pollution that exists because of natural causes like dust, etc. India makes up for some of the lack of ground-level pollution monitoring by watching things from space. Satellite based data monitoring has been around for the past twenty years. Dey believes that this data must be used to deploy ground-based costlier reference monitor stations across India.

They further talk to Rohit Bansal of Purelogic Labs. They have a website called which tries to provide low cost sensors. Sensors have become really good and really cheap in the last three years. So much so, that their quality is slowly moving towards the levels of reference monitors. Where, reference monitors cost in the range of $15,000-$20,000, low cost sensors are available for $20-$40 range. There are efforts to make these sensors as good as the reference monitors. Bansal says that the quality of reference monitors also needs improvement.

The third episode is about governance. They talk about the umbrella Environmental Protection Act, 1986. These provide standards, emission standards and working of the Pollution Control Boards. They talk about India moving from BS IV directly to BS VI, about how PCBs can issue notices but can’t collect the charges levied on them. I didn’t grok this episode because it slipped on the side of law and governance.