After the success of the first ever robot landing on a comet last Wednesday, Her Campus catches up with UCL’s Mullard Space Science Laboratory PhD student Yudish Ramanjooloo to see what’s next in this exciting space age.
L: Yudish, tell us a bit more about yourself and your PhD.
Y: My thesis title is Comets as natural laboratories: Interpretations of the structure of the inner heliosphere, I’ve been working on it for 4 years. I took a 14 month sabbatical in the middle when I had the opportunity to work in an observatory on La Palma, an astronomical hotspot. My supervisors are Dr Geraint Jones and Prof Andrew Coates.
Picture taken by Philae on its descent, Nov 12, 2014 from a distance of approximately 3 km from the surface. ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0
L: Why send a robot and not a man (or woman) to the comet, is it even possible to send a person to do these experiments?
Y: Good question, let me first mention that my knowledge on space missions and our current capabilities are limited and by no means, should my answer qualify as a complete answer.
Technically, we should be able to land a man or woman on a comet. The knowledge, expertise and experience is there from past missions. However, missions to outer space are tricky and expensive. There’s no sensible way to justify the costs of sending an astronaut to a comet when a robot will do. I am sure you wouldn’t be surprised that the government and the public might be reticent to that idea when a robot can do multiple jobs at a much cheaper cost. The orbiter and the lander contain 23 different instruments, that’s 23 different experiments.
Remember we have only ever sent man to the moon. I don’t think it would be a good idea right now, as there would be no added benefit to the mission. If you were to send a man there, he would need to take water, food, special protective clothing, oxygen etc. The amount of fuel needed to take the rocket, the astronaut and equipment out into space would be much more than what it took for a 3 ton spacecraft and its 100kg lander. You also need to think of the psychological effect of a long journey alone in space and landing on a comet.
Although a cool fact about the comet is that its low gravity means that a human could easily reach its escape velocity (the speed at which you’d need to travel to leave the gravitational pull of the comet) by simply leaping off of it.
L: Why is this mission important, in your opinion?
Y: Rosetta (orbiter) and Philae (lander) is the first mission of its kind. Catching up to a fast moving comet, with speeds up to 135,000km/h, orbiting (this means we had to accelerate our spacecraft with multiple gravity assists to the same speed as the comet) and then landing on it, was extremely ambitious and difficult. We’ve done it. Now that we’ve proved it can be done successfully, it paves the way for more adventurous missions in the future to produce more ground-breaking advances in science and technology.
This is one of the most fantastic and daring missions that humankind has attempted. The mission cost approximately 1.4 billion euros. Plans started in 1996 and the spacecraft was launched in 2004. The trip has taken 10 years and has already contributed to the total sum of human knowledge.
We also need to bear in mind that this is a collaborative effort from multiple countries with employees from multiple nationalities. This is a global collaboration of individuals from different races, genders, cultures and faiths with one goal: net gain for humanity and science. This historic moment should serve as an example of what we can accomplish. In this day and age when strife is commonplace on the news, the relationships and teamwork shown by the ESA team should be highlighted.
First ever panoramic image from the surface of a comet. ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0
L: Now the robot has landed on the comet, wait a minute, does this comet have a name?
Y: Yes it does, Comet 67P/Churyumov–Gerasimenko, Comet 67P or C-G for short.
L: So yeah, now the robot’s landed on Comet 67P, what happens now?
Y: Rosetta will follow the comet as it enters our inner solar system, as the comet gets closer to the Sun, its dynamics will change, as will its activity. With both the lander and the orbiter, we can study the comet as it evolves. As it is, we have already gathered an extensive amount of ‘first of its kind’ scientific data, from the flybys of asteroids Steins and Lutetia to the 3-4 months that the orbiter has already been at the comet.
L: What are the reasons for studying comets?
Y: The popular theory of the origin of water, to date, is that when the Earth formed, comets crashed into the early earth, bringing water and other complex organic modules with them. Our current paradigm for planetary formation is that comets are remnants of the early solar system, formed from the same dust and ice grains as the Earth, but in formed in outer regions of the solar system. By studying comets, we can obtain glimpses into the composition of the original building blocks of our solar system and how they have evolved in 4.5 billion years.
L: Why do we need to know about its composition?
Y: So not only does it allow us to get a snapshot, or a window into the past of our solar system, it could help us in the future. Though tiny, comets are complex in nature. They are natural probes of our solar system and understanding their composition in further detail is key. If we ever find a comet on a collision course with earth, with the knowledge of its surface properties, we can work out how to deflect the comet or destroy it should that ever happen.
Comets come, not only, in many different shapes and sizes but also in composition. They are also pristine remnants of the solar system as it formed about 4.5 billion years ago, remaining mostly unchanged underneath its crust. Investigating the composition of 67P would be the first step in helping us classify comets by composition, which could help us gain a better understanding of the composition and distribution of primordial material that made up the early solar system.
L: How likely is a comet collision with Earth?
Y: Very unlikely. It is impossible to say as there are a large number of potential comets that have yet to be discovered. They are the most abundant objects in our solar system but most of them are small and very far away, making it difficult to compute an exact number. The reservoirs of comets are far out in the solar system and the only way we can detect a comet at the moment is to scan the sky for fast moving, brightening objects. Those that we do know of present no danger for the foreseeable future. However, we do need to fund observations of the night sky to make sure we catch any potential impactors long before they pose a threat. We do have concerns about near-earth asteroids (NEAs) though, but there are several surveys that have been set up to scan the night sky. Those NEAs have a higher risk of impact but again for the foreseeable future, there are no risks on that front.
How can those interested keep up to date with this mission/learn more about comets? Can you recommend any extra information for our readers?
Y: All the images are available under the Creative Commons licence from the ESA [European Space Agency] website. The orbiter has been following the comet since August and it will carry on until at least 2016 so there is still ample opportunity to learn more. You can also read an article I wrote on comets and how the public can help to explore the inner heliosphere.
L: Thanks for your time Yudish, it’s been great finding out more about this mission and comets.
Keep up to date with the latest developments in this particular mission here and find live twitter updates from Philae here!
Image Sources
http://www.esa.int/spaceinimages/Images/2014/11/ROLIS_descent_image
http://scienceogram.org/blog/2014/11/rosetta-comet-esa-lander-cost/
http://www.esa.int/spaceinimages/Images/2014/11/First_comet_panoramic
Edited by Sam Carey