Dr. Thomas Z

Originally Published: April 9, 2017

A few weeks ago, NASA announced a stunning news-story which became one of the biggest NASA science stories ever: over 3 billion interactions with NASA’s online content, hundreds of newspapers (including New York Times) carried the story on the front-page, tens of thousands of articles were written in the worldwide press, and a Google Doodle topped it all off (https://www.google.com/…/seven-earth-size-exoplanets-discov…).

The story is compelling: Based on NASA Spitzer observations, Trappist-1 is a newly discovered mini-solar system with 7 rocky planets, 3 of which in the habitable zone where water can pool on the surface. This post is about things that happened since, and that shows how exoplanet research is becoming increasingly inter-disciplinary.

A couple of weeks after the initial announcement, Kepler on its K2 mission provided 74 days of monitoring of the Trappist-1 system and its cosmic neighborhood (https://www.nasa.gov/…/nasas-kepler-provides-another-peek-…/). Within 2.5 hours, the first tweet came out indicating a result: An astronomer had found a second pass of planet H, the outer-most planet. Within weeks, that result was already summarized online as part of the arXiv e-print series (http://adsabs.harvard.edu/abs/2017arXiv170304166L): planet H is at the snow-line, beyond which water can exist only in its frozen state. Many of the other results of the initial paper were also confirmed. Obviously, these results (as well as others mentioned below) will have to go through review before the results are fully accepted.

The data also provided important additional information about the activity of the star. Just like our Sun, Trappist-1 has magnetic activity that leads to flares. In fact, astronomers know that this type of dwarf star tends to have a very violent past when it comes to stellar activity – possibly providing an important ingredient whether or not life can persist on this planet.

One researcher told me that using the data about the magnetic field known from this star, it seems that the field is such that the planets sit in a subsonic part of its stellar wind, and not the super-sonic part as all planets here in the solar system. If this is correct, the Trappist-1 planets have a fundamentally different space weather environment than the Earth with stellar wind coming towards them from all directions, not just from the direction of its star.

There is another result that is important in this context, and this one is from our neighborhood – from MAVEN, currently orbiting Mars. Based on their data of atmospheric loss of specific components, the team concluded that Mars lost most of its atmosphere and its water during its history, making it far less hospitable than the Earth. According to the authors, the culprit for this loss is the absence of a global-scale magnetic field that suppresses such loss to space. Do Trappist-1 planets have magnetic fields? We don’t know at this point.

Finally, a submitted paper by Wolf (https://arxiv.org/abs/1703.05815) does the first analysis of a climate model for the Trappist-1 planets. Needless to say, there are lots of assumption in there, put the paper points out that – under several assumptions – planet E has the best chance to be a habitable world. To me, the paper indicates how many observations about the planets’ atmospheres we need to make to actually nail down some of the very hard questions about the habitability of these strange worlds.

In summary, the Trappist-1 discovery announced a few weeks ago is already spurring research that goes far beyond the initial observations. The follow-up studies give an indication that to answer the fundamental question: “Is there life out there?”, is a fundamental question that will require scientific breakthroughs from many different science fields, including ones who currently are not deeply engaged in this exciting research.

This demonstrates the nature of great research: it’s not just about answering questions that have been asked in the past, it is about asking entirely new questions that will have impact for a long time to come!

Originally Published: February 12, 2017

It took nearly 100 years for predictions about frame-dragging, a direct consequence of Einstein’s theory of general relativity published in 1915, to be confirmed using a sophisticated analysis of three spacecraft in orbit about the Earth. The Earth is very, very slowly dragging space with its rotation, subtly changing satellite orbits, as predicted by two Austrian scientist in 1918, and finally confirmed at the <10% level around 2010.

It also took more than 100 years for the ground-based Laser Interferometer Gravitational-wave Observatory (LIGO) to make the first observations (announced almost exactly 1 year ago!) and to confirm one of the most fundamental predictions of the same theory – the existence of gravitational waves. This prediction has ignited more interest in space-born detections of these waves by spacecraft such as LISA, the Laser Interferometer Space Antenna, which will open up a whole new window into the universe.

It will have taken 60+ years for NASA’s Solar Probe mission to launch in 2018 in order to test the fundamental predictions made by Parker in his profound 1957 paper that almost was rejected by reviewers. It just seemed too unlikely – why would the Sun eject supersonic plasma that fills space? Now, we are finally building the spacecraft to examine the solar wind where it matters most, at its source.

Sometimes, doing the best science takes a lot of time! It turns out that the most important physical effects we seek to confirm are extra-ordinarily subtle or tough to access.

To do the frame-dragging experiment, we had to learn how to launch spacecraft, how to shoot lasers at them and to measure times and positions at highest accuracy. It took a deep understanding of radiation pressure forces and also of the Earth gravity field and levels we could only imagine in the 1900s.

The engineering challenges for LIGO almost seem hopeless: detect motions of scales of 1/1000 of an atomic nucleus. Build 4 km long vacuum chambers, and do so twice, 3000 km apart, but in precise coordination. It seems hopeless when you start, but it leads to the best science and it launches a storm of innovation to make it reality.

So, what does it take to get so close to the Sun that you can observe the waves that accelerate the solar wind? You need to be at 10 solar radii, with nearly 50,000 more heat hitting the spacecraft surface than near Earth. To survive this heat, one has to invent a thermal protection system that not only can survive, but do so that the sensitive science measurements next to them are still possible. The spacecraft has to be on auto-pilot for some of the most important phases. It is really, really hard!

Looking at history, it turns out, that we always need to invent some totally new and innovative technologies to enable new ambitious science. This interplay between ambitious science and innovative technologies is one of the most impactful aspects of NASA’s science program. Projects like LISA, the James Webb Space Telescope, or Solar Probe are like science moon shots: We invent all the steps of the path till we finally get the desired goal!

This science-driven technology development not only enables scientific leadership, it also feeds an innovation engine with impacts that are well beyond the realm of the initial question and application space. We know about the economic impact of the Apollo program, and we are in awe about the broad applicability of space technologies for National defense, our technological leadership and also our economy. And in rare cases, our observations we make in space change everything, even the way we think! There is nothing more profound than that.

Broad and lasting impacts are not coming from playing it safe, they come from ambitious science driving innovative technology. Note that we have a NASA science program that has a variety of tools with different objectives. But, when it comes to breakthrough science, playing it safe intellectually does not cut it!

Final point: intellectual ambition is not proportional to the cost of a system. In fact, the most entrepreneurial solutions are the ones that pair intellectual ambition with nearly impossible financial constraints!

Originally Published: February 4, 2017

Last week, I did my first trip abroad as Associate Administrator of Science at NASA, visiting both Switzerland and France.

My first talk was to an audience of about 600+ at the University of Bern, my alma mater. I started my presentation by announcing that we were making history today since I was the first NASA Associate Administrator to give a science talk in German (pic below from U Bern). I had prepared for over four hours to ensure that i knew all the words. During this chat, I discussed the impact that science has in the world. From benefiting humanity on Earth, to the importance of fundamental research, the science that NASA does on a daily basis is critical.

I also gave a lunch talk in Swiss German three days later where I focused on the power of innovation and leadership in organizations. The next day, I finally gave a talk to a French audience. Even though I took some questions in French, I did not dare give my talk in French just having arrived in Paris the day before.

Originally Published: Jan. 21, 2017

I spent the weekend home in Ann Arbor, with my family. I made that decision after receiving a message from the people running my apartment-house in DC telling me to stay away from windows and off balconies during the Inauguration related events.

In fact, I was glad to spend time in Ann Arbor and I even had time to visit some friends and former colleagues at the University of Michigan and do an interview for Gary Krenz’s Bicentennial activities. The interview made me think because of a question he asked that was very hard to answer. It was a question about “my home” and how I feel about it.

Originally Published: Jan. 14, 2017

Living in D.C., I get a unique front-window view on US politics and learn about the country in a new and unprecedented way.

Right now, the entire city is buzzing about the inauguration and the peaceful change of power that is typical of presidential transitions since the beginning of the US. Last week, the entire county listened to current president and his associates reflect on his last 8 years of presidential politics. We watched the vice-president’s tearful reaction when he was surprised by his friend, the president, awarding him the medal of freedom, with distinction. Yes, this change is filling the news worldwide. But there are things you only see in DC.

Originally Published: Jan. 7, 2017

Sensing the environment of black holes and the origin of high-energy cosmic rays, exploring the early building blocks of the outer solar system, and a journey to the metal-world of a planetary core – these are the science investigations NASA announced this week, my first three selections as an Associate Administrator.

Imagine sitting in a room for many hours and listening the the sales pitches of mission finalists. Each pitch is exactly an hour and highly regulated with respect to its contents and participants of the pitch. The team is nervous and worried, trying to interpret every move you make, where you look and second-guess what each question means that you ask. This is what I did during December – eight times over.