Astronomy

See Asteroid 2012 TC4’s Trip Past Earth


 
On October 12, 2017, asteroid 2012 TC4 passed Earth early in the morning, flying above Antarctica at around 1:42am EDT.
 
See its close approach in Universe Sandbox ²:
Home > Open > Historical > 2012 TC4 Passes Earth on October 12, 2017
 
The roughly house-sized asteroid passed just a bit beyond the orbits of communications satellites, well within the Moon’s orbit. This wasn’t close enough to pose any threat, but its orbit was slightly changed by Earth’s gravity, as you can see in the GIF above from Universe Sandbox ². Learn more on NASA’s website
 
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Cassini’s Limitations in Universe Sandbox ²

It’s been two weeks now since we said goodbye to the Cassini spacecraft. After its 20-year-long mission in space, it was running low on fuel, so NASA directed it toward Saturn in order to eliminate the risk of it contaminating the moons. On September 15, 2017,  Cassini sent its final image back to Earth before disintegrating in Saturn’s atmosphere.

To commemorate this event, we released Ciao, Cassini | Update 20.2 which featured a simulation of Cassini’s final hours and collision with Saturn.

See Cassini’s final hours in Universe Sandbox ²:

Home > Open > Core/Historical > Cassini collision with Saturn on September 15, 2017
Home > Tutorials > Science > What Is Cassini’s Grand Finale?

Simulation Limitations

We had initially been wary of including a simulation of this event, as there are several limitations in Universe Sandbox ² that reduce the realism of this particular simulation. In the end, however, we decided it was still an informative and interesting visualization of an event that is very important to science and the world.

But instead of brushing these limitations under the rug, we’d like to take a closer look at them.

1 – Atmospheric Entry

We love collisions in Universe Sandbox ². But just because an object is on a collision course with a planet, that doesn’t mean it should actually collide with that planet in every scenario. If it’s small enough, then it should instead disintegrate in the planet’s atmosphere. This is what happened to Cassini as it entered Saturn’s atmosphere.

Universe Sandbox ² doesn’t yet simulate the forces associated with atmospheric entry, like atmospheric drag and aerodynamic heating. So instead, small objects will simply collide with planets. We’re very interested in simulating these effects in Universe Sandbox ², not just for objects like Cassini, but also for meteoroids that should burn up in an atmosphere, creating meteors or “shooting stars.”

Meteoroid meteor meteorite.gif
An animation from Wikipedia of a meteoroid losing material as it enters Earth’s atmosphere

 

2 – Rocket Engines & Spacecraft Flight

Cassini didn’t stay in orbit around Saturn for 13 years, weaving through its rings and doing close flybys of its moons, all by the grace of gravity. No, its trajectory was carefully planned by engineers and frequently adjusted with its rocket engines. But while Universe Sandbox ² has models of various spacecraft, it doesn’t yet include any way to simulate or control propellant. You can manually change an object’s velocity, but you can’t apply a force to it in the same way that a rocket engine would.

We’re still a while away from controlling thrust on spacecraft and flying them through simulations in Universe Sandbox ², but we’re taking steps in that direction with our work on rigid body physics. This new tech will better simulate the physics of smaller-scale objects, such as spacecraft, allowing for precise collisions and parts that can be attached with breakable joints and other constraints.

 

3 – Minimum Size for Impact Visuals

When the Shoemaker–Levy 9 fragments collided with Jupiter, observers from Earth could see marks on Jupiter that were more easily visible than the famous Great Red Spot. Some of these fragments were larger than one kilometer in diameter. The Cassini spacecraft, on the other hand, was only about 6.8 meters high and 4 meters wide. Its disintegration in Saturn’s atmosphere should not be easily visible, and even if it were to collide with Saturn instead of disintegrating, it should not leave a large impact mark. [Our Cassini update added a quick fix for this problem to disable an impact mark for its collision.]

Unfortunately, in Universe Sandbox ², impact marks have a minimum visual size. This minimum size is much larger than it should be for small asteroids and human-sized objects. The alternative is to not show any impact mark at all, but that can also be unsatisfactory. There are technical reasons for this limitation, but let’s not worry about those, because there’s good news…

We are currently working on a new system which will allow for impact marks and craters of any size, no more minimum. And on top of that, the new system will be a lot faster, too, and scale to the system resolution, which should help lower-end hardware a lot.


Work-in-progress screenshot of the new impact visuals in Universe Sandbox ²/span>

Opportunities, Not Limitations

The first rule of self-criticism (which we didn’t follow above) is that it’s necessary to throw things in a positive light. Drawbacks, weaknesses, limitations — they’re all opportunities for improvement! Often times these simulations of historical events are great tests of the simulation. When we put in the known properties and velocities for a set of bodies, does the simulation play out similarly to how it did in observed reality? If something is different, how can we improve the simulation in order to achieve the same results?  But if instead it’s remarkably similar, as it sometimes is, then we can give ourselves a nice pat on the back and sit back and relax… Until we load a different simulation and notice another opportunity for improvement. We often say that building a universe simulator is never a completed job. A big chunk of that lies within our commitment to continuously notice where we can improve, and then take the necessary steps to make these improvements.

The above items are all on our to-do list, though we can’t promise when they will be added to Universe Sandbox ². Learn more about what we’re working on in our 2017 Roadmap.

For the latest Universe Sandbox ² news, follow us on Twitter and Facebook.

Ciao, Cassini | Update 20.2

Run Steam to download Update 20.2, or buy Universe Sandbox ² via our website or the Steam Store.

November 3: Updates 20.2.3 and 20.2.4 are small updates which add two sims from the latest Vsauce video as well as a few improvements and bug fixes.

November 2: Update 20.2.2 is a minor update which includes a number of improvements and bug fixes.

October 5: Update 20.2.1 a minor update which adds a Cassini spacecraft model, Quicksave & Quickload (F5 & F9), and a number of smaller improvements and fixes.

 

On September 15, 2017, the world says goodbye to the Cassini spacecraft as it ends its historic mission with a final plunge into Saturn.

During its 13 years orbiting Saturn, Cassini made a number of invaluable discoveries about the planet, its rings, and its moons.

We now know that massive geysers covering the south polar region of the moon Enceladus shoot icy particles into space, forming most of Saturn’s E-ring and hinting at a massive, subsurface ocean. And we now know that the surface of Titan, Saturn’s biggest moon, shares a surprising number of characteristics with Earth, including dunes, mountain ranges, rivers, lakes, and seas.

With its array of sophisticated instruments, Cassini watched as storms raged on Saturn and seasons changed. It discovered eight new moons, provided insight into the behavior of its famous rings, and completely changed our understanding of its magnetosphere. The mission has been extended twice and now Cassini has been in orbit nine years longer than originally intended. Its fuel is nearly gone and so, to prevent possible contamination of any of the moons, its course has intentionally been set for disintegration in Saturn’s atmosphere.

So now we say ciao, Cassini. Thanks for all of your work.

And thanks to all of the hard-working scientists from NASA, the European Space Agency, and the Italian Space Agency who made the Cassini mission possible.

See Cassini’s final hours in Universe Sandbox ²

Home > Open > Core/Historical > Cassini collision with Saturn on September 15, 2017
Home > Tutorials > Science > What Is Cassini’s Grand Finale?

This update also includes a number of smaller improvements and bug fixes.

Check out the full list of What’s New.

 

For the latest Universe Sandbox ² news, follow us on Twitter and Facebook.

Science Works. Science Helps. Science Matters.


Observation. Hypothesis. Prediction. Experiment. Refine. Begin again.

Science is neither truth nor faith. Science is the process by which we reject or refine testable theories. These theories explain and predict the rules and processes that govern the behavior of the natural universe. Science doesn’t find universal objective truth; it narrows the error bars of our understanding. By its very definition, the scientific method works: if it is not reproducible, if it is not predictive, or if evidence rules it out, then it is rejected by science. And if it isn’t testable, then it isn’t in the realm of science (instead I would argue it is– and should remain– personal).

Science solves problems, and it solves them efficiently. Science makes us healthier, safer, more comfortable, and better at solving the problems of our daily lives. Applying the rigor of science to any decisions or areas of understanding that affect the lives of others can only serve to benefit lives and minds (for major decisions, not for when a friend wants you to choose the restaurant). Observation, hypothesis, prediction, experiment, analysis, adjust, rethink, repeat. We use the scientific method to make better meals, we can trust it to pick our diets, we can use the method to choose the best products, or to determine the best route to work.

Science and skepticism go hand in hand. We build our understanding of the world based on our observations of it, but also by the input of others. We can understand logical fallacies, accept new data, and test our assumptions against that data. In doing so, we can constantly refine and adapt our worldviews, and we can grow as people.

Science is not a political issue. The beauty of science is that it has to be reproducible and predictive. That means you don’t just have to believe what you are told. You can check for yourself! Some things might require expensive labs to verify, but if you, say, thought the world was flat, well you can check that!

Universe Sandbox ² is a live simulation that takes our understanding of the motion of objects and uses it to decide where each body will move as we step through simulation time. This matches closely to reality (at reasonable time steps, for non-relativistic situations) because science is reproductive and predictive. Society’s current understanding of physics allows us to send missions like Rosetta, or Juno, or New Horizons, billions of miles away to planned locations with an error equivalent to “throwing an object from New York and having it hit a particular key on a keyboard in San Francisco.”

Because this is how science works. Ignoring actionable, well-established scientific predictions is unconscionable. It’s plugging your ears and going “la la la” when someone tells you there’s an atrocity happening right behind your back, an atrocity that you have the power to stop. Not only can you turn your head and easily verify that the person is speaking the truth, but you can even do something to help, and instead you choose not to. Our choice cannot be to ignore this. Our choice matters. So today, I march for Science.

To very loosely quote Hank Green:
Science increases the Awesome and decreases the Suck in our world, and for that reason, I will always love it.

A note: I don’t want people confusing scientific institutions and cultures with the method itself. It is important to acknowledge the biases and failings of our scientific institutions historically and at present, especially with regard to equality and intersectionality, but let us not convolute science with academia or STEM institutions.

Celebrating Our Rare and Special Planet on Earth Day

Universe-Sandbox-²-Earth Day

I hear a lot of people say that looking at our universe from a solar system, galactic, or cosmological scale makes them feel small and insignificant. Insignificant to who and what? I look at our universe and I see the incredible complexity that has arisen from a few forces and a few fundamental laws. You see it in the structure of the cosmic background, you see it in the shapes of galaxies, you see it in the heavy elements formed in our stars. Nowhere do you see that complexity more than when you look at life. It was a glorious accident that allowed us to exist, and we exist in an incredibly delicate balance.

99.99999999…% of the universe is empty space. 99.9999999…% of that which is not empty space is lifeless. Why does it matter if somewhere light years away something doesn’t care about your individual existence?  We have this amazing planet and it might not be unique in the universe in its complexity, but it is incredibly rare and special, and I feel very significant — overwhelmed with a sense of purpose and duty, in fact — because it is up to us to try as hard as we can to preserve this rare and special place and all the life on it.

The structure of the universe doesn’t make me feel insignificant. It makes me feel incredibly lucky. By some chance I exist in this rare place. Thus it is my duty to try to keep life existing here, and to try to make that life as pleasant as possible for the other rare and lucky creatures who share it with me.

– Jenn Seiler, astrophysicist and Universe Sandbox ² developer.

 

Learn how we simulate Earth’s climate and how you can explore it in Universe Sandbox ²:

 

Gravitational Waves & Universe Sandbox ²

A black hole in Universe Sandbox ². Researchers have concluded the gravitational waves they detected were the result of two black holes colliding.

A black hole in Universe Sandbox ². Researchers concluded the detected gravitational waves resulted from two black holes colliding.

What’s the significance of discovering gravitational waves?

This announcement is a huge deal.  It is on par with the discovery of the Higgs Boson particle which provided the missing evidence for a prediction of the Standard Model of particle physics. Gravitational waves are a century-old (almost exactly) prediction now confirmed by a huge number of relentless, and brilliant people after many years of hard work. It is the first direct confirmation of the prediction from Einstein’s General Relativity that matter and energy determine the motion of bodies by warping the fabric of spacetime itself, and in so doing, emanate ripples when massive bodies are accelerated through that space.

It is not only confirmation of general relativity, though. It is also the first of many future observations that will look at the universe in a completely new way. Up until now we’ve used only photons (telescopes all along the electromagnetic spectrum) and sometimes neutrinos. Now we can add listening to the fabric of space to our list of tools. This will allow us to see the dark and the obscured parts of the universe: the early universe, centers of galaxies, things blocked by dust clouds, and so on, by listening for changes in space itself. It is the start of a new age in astronomy.

In addition to this detection being the first direct proof that the predictions of general relativity that matter and energy warp space time are true, and some of the strongest evidence for the reality of black holes, this is also a new kind of astronomy.  Though gravity is the weakest force and gravitational waves are very hard to detect, they do have a few advantages over observations of photons.

  • First, gravitational waves are practically impervious to matter in their path. This means we can see into regions of space that are blocked to optical observatories, such as inside dense clouds of dust, the centers of galaxies, behind large or close bodies.
  • Second, this is an observation of the warping of space itself, meaning we can detect things that have mass but might not produce observable light, such as black holes, dense sources of dark matter (if such were to exist), cosmic string breaks, etc. 
  • Third, gravitational waves fall off in amplitude much more slowly than light. This means that we can receive signals from very far away that we might not notice optically.
  •  And fourth, because gravitational waves also travel at the speed of light and don’t have to bounce off intervening matter, and begin to be potentially detectable from bodies getting close rather than just after the moment of collision, this means that we can work with other telescopes and tell them “Look over there! You’re probably going to see something exciting!”

This all of means that this detection means the beginning of a new kind of observational astronomy, as well as a better understanding of of of the fundamental forces of the universe, gravity.

 

What role did Jenn, astrophysicist and Universe Sandbox ² developer, play in the discovery?

While I was in the field I ran super-computer simulations to make predictions about the gravitational wave signals that would be produced by binary black hole mergers. Those waveforms are used as templates in the detector pipeline. The detector matches the template banks against the incoming data to find real signals amidst the noise of the detector, while also doing searches for large burst signals (how this one was found). Those waveforms are then used again to determine where the signal came from, what it was (two black holes, a neutron star and a black hole, two neutron stars, etc), and the properties of the bodies that created the signal (spins, masses, separation, etc.). I also worked on developing the analytical formulas to determine those spins and masses from those signals.

Here’s one of the scientific papers on the process of determining the properties of the source of the signal, with three papers cited on which Jenn Seiler was an author:

https://dcc.ligo.org/public/0122/P1500218/012/GW150914_parameter_estimation_v13.pdf

The Einstein equations for general relativity are ten highly non-linear partial differential equations. This means that it is only possible to obtain exact solutions for astrophysical situations for some very idealized conditions (such as spherical symmetry and a single body). In order to predict the gravitational waveforms produced by compact multi-body systems, or stellar collapse, it is necessary to solve the equations numerically (computationally). This means formulating initial data for spacetimes of interest (such as two in-spiralling black holes of various spins and mass ratios) and evolving them by integrating the solutions of the Einstein equations stepping forward in time by discrete steps. To prove that these computer simulations approximate reality more than just by equations on paper we would run these simulations at multiple resolutions for our discrete spacetimes and show that our solutions converged to a single solution as we approach infinite resolution (that would represent real continuous space) at the rate we expect for the method we were using. 

There were many obstacles in creating these simulations: vast amounts of computational power required for accuracy; the fact that we needed to run tons of these large, slow, computationally intensive simulations in order to cover the parameter space (spins, masses, orientations, etc) of potential sources of gravitational waves; and so on. For black holes, one major challenge was the fact that they contain a singularity. A singularity means an infinity, and computers don’t like to simulate infinities. Numerical relativity researchers had to find a way to simulate black holes without having the singularity point in the slicing of the spacetime integrated in the simulation. The first successful simulation of this kind didn’t happen until 2005 (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.95.121101).

Once we had working simulations, groups around the world set to work on simulating the gamut of major potential gravitational wave signal sources. These simulation results were not just useful to the detectors to help identify signals, but also to the theorists to help formulate predictions about the results of such astrophysical events. Predictions such as: the resulting velocity of merged black holes from binaries of various spins, the amount of energy released by black hole mergers, the effect that black hole spins have on the spins and orbits of other bodies, etc.

When will you add gravitational waves into Universe Sandbox ²?

We really can’t do gravitational waves in an n-body simulation, which is the method Universe Sandbox ² uses to simulate gravity. N-body simulations look at the effect that each body has on each other body in a system at small discrete time steps.

General relativity requires simulating the spacetime itself. That is, taking your simulation space, discretizing it to a hi-res 3-D grid and checking the effect that each and every point in that grid has on all neighboring points at every timestep. Instead of simulating N number of bodies, you are simulating a huge number of points. You start with some initial data of the shape of your spacetime and then see how it evolves according to the Einstein equations, which are 10 highly non-linear partial differential equations. Accurate general relativity simulations require supercomputers.

There are some effects and features related to relativity that would be possible to add to Universe Sandbox ², however. Here are a few we are discussing:

  • Gravity travelling at the speed of light.

    • Currently if you delete a body in a simulation, the paths of all other bodies instantly respond to the change. The reality is that it would not be instantaneous; it would take time for that information about the altered gravitational landscape to reach a distant object.

  • Spinning black holes.

    • Most black holes are very highly spinning. If you imagine a spinning star collapsing it is easy to understand why. This is the same effect as when a spinning figure skater pulls in their arms; because of conservation of angular momentum, they spin faster. A consequence of this spin is that, while the event horizon would remain spherical, there would be an oblate spheroid (squished ball) around the black hole called an ergosphere. This ergosphere twists up the spacetime contained within it and accelerates bodies that enter this region (as well as affecting their spins). Because it is outside of the event horizon, this means one can slingshot away from this region and even steal energy from the rotation of that black hole.

  • Corrections to the motions of bodies to approximate general relativity.

    • Loss of momentum due to the emission of gravitational waves causes close massive bodies to inspiral. With this you could recreate the decaying orbits of binary pulsars.

    • Spins of close bodies affect each other’s motion and spins (see above). This would give you things like spun up accretion disks around black holes.

    • These corrections would be made by adding post-newtonian corrections to body velocities.

 

Learn more

Bad Astronomy article: LIGO Sees First Ever Gravitational Waves as Two Black Holes Eat Each Other

Video and Comic Explaining Gravitational Waves

Reddit AMA (Ask Me Anything) by LIGO Scientists

Paper by LIGO Researchers: Observation of Gravitational Waves from a Binary Black Hole Merger

Alpha 18.2 | Planet Nine | Now Available

Planet Nine

The discovery of a hypothetical ninth planet in our solar system was announced on January 20th, 2016 by researchers at the California Institute of Technology.

Universe Sandbox ² Alpha 18.2 features two simulations of Planet Nine. Run Steam to update, then check them out in Home -> Open -> Possible Planet Nine [and] Evidence of a Ninth Planet. 

Or buy now for instant access to Universe Sandbox ² on Steam Early Access:

http://store.steampowered.com/app/230290/

http://universesandbox.com

The announcement comes after years of research into explaining the peculiar, but very similar, orbits of six small bodies orbiting beyond Neptune. Many theories have been proposed, but none has been as compelling as a very distant ninth planet pulling these bodies into their highly elliptical orbits. Using mathematical modeling, the two researchers, Konstantin Batygin and Mike Brown, have shown that a ninth planet fits very well into the data we have about objects in the Kuiper Belt and beyond.

There's only a 1 in 15,000 chance that the clustering of the orbits on the left is coincidental. Another explanation is the gravitational influence of a ninth planet, whose orbit is represented by the yellow line on the right. (from Universe Sandbox ²)

There’s only a 1 in 15,000 chance that the clustering of the orbits on the left is coincidental. Another explanation is the gravitational influence of a ninth planet, whose orbit is represented by the yellow line on the right. (from Universe Sandbox ²)

Planet Nine has not been directly observed yet by telescope, which is why it is hypothetical. But the researchers say there is a very good chance of spotting it in the next five years. It is suspected to be about 10 times the mass of Earth, similar in size to Neptune, with an orbit that’ll take it around the Sun every 10,000 – 20,000 years. 

Of course, we don’t know how Planet Nine got there. Brown and Batygin propose that this planet was formed in the early days of the solar system, along with Jupiter, Saturn, Uranus, and Neptune. Then it could have been shot outward by one of the gas giants, and instead of leaving the solar system entirely, it may have been slowed down by gas in the Sun’s protoplanetary disk, enough to keep it in orbit.

Universe Sandbox ² - Planet Nine Alt Angle

Alternative angle of Planet Nine (yellow orbital line) and the six objects used in the analysis. (from Universe Sandbox ²)

If the ninth planet does exist, then it will be the second time our solar system will have claim to nine planets… After, of course, Pluto was demoted in 2006. But Brown says there’s no question that the hypothetical ninth planet is indeed a planet. It’s likely much bigger than Earth, and has a large influence on other bodies in the solar system. And besides, Brown would know — his discovery of Eris was the reason Pluto was voted out.

Here’s a great discussion of Planet Nine by Mike Merrifield, an astronomer and professor at the University of Nottingham:

We’re hope you’re as excited about this possible discovery as we are! Make sure you check out the new simulations in Universe Sandbox ²: Home -> Open -> Possible Planet Nine [and] Evidence of a Ninth Planet.

See the complete list of What’s New in Alpha 18.2:  What’s New

 

Additional links about Planet Nine:

Astronomers say a Neptune-sized planet lurks beyond Pluto 

Evidence grows for giant planet on fringes of Solar System

Evidence for a Distant Giant Planet in the Solar System (research paper)

Simulating the World of Game of Thrones in Universe Sandbox ²

Universe Sandbox ² - 20150707-140519 UI

An Unpredictably Long Winter is Coming

Fans of George R. R. Martin’s fantasy series A Song of Ice and Fire or the television series, Game of Thrones, know well the often repeated warning, “Winter is coming.” 

For those living on the continent of Westeros in this fantasy world, summers can be long, and so can the winters. But some winters are especially cold and last for several years, while others are relatively mild and short.

What causes this variance in seasons?  Martin doesn’t offer an explanation, so we’re free to speculate.

One research paper (“Winter is coming”) proposes that perhaps there’s a natural explanation: Westeros is on a circumbinary planet, meaning its orbit extends around a binary star system.

Simulating  Westeros in Universe Sandbox ²

The paper may be tongue-in-cheek, but that doesn’t mean we can’t use its parameters to try simulating it in Universe Sandbox ². Like the paper, we were unable to find stable orbital parameters that would create the level of unpredictability discussed in the books or the show.

We could, however, create a system that has variable winter and summer intensities on regular predictable intervals with a large northern polar ice region. Though our results didn’t exactly match those in the paper, we managed to recreate similar seasonal patterns to what the authors describe in their paper.

If you own Universe Sandbox ², you can see this simulation for yourself in Alpha 15: Home -> Open -> Fiction -> Lands of Ice & Fire | Game of Thrones.

To open the temperature graph, open the Westeros planet’s Properties, select the Climate tab, hover over the Surface Temperature icon and click the Graph button.

If you don’t own Universe Sandbox ², you can buy it now to get instant access to the alpha via Steam code: http://universesandbox.com/2

Universe Sandbox ² Alpha 15.2 | The Pluto Encounter Update

Universe Sandbox ² - New Horizons Pluto 2

If you already own Universe Sandbox ², just run Steam to update to the latest version.

Or you can buy Universe Sandbox ² here:
http://universesandbox.com/buy/

New Horizons

We’ve just released Alpha 15.2, which features a simulation of NASA’s New Horizons trip past Pluto and its moons. The spacecraft will be closest to the icy dwarf planet next Tuesday, July 14th. You can find the simulation in Home -> Open.

We will be updating Pluto’s and its moons’ textures as data is received from the New Horizons spacecraft.

If you keep the simulation running to 2019, you will see New Horizons approach its second target, 2014 MU69 (or PT1), an object with a diameter of 30-45 km orbiting in the Kuiper belt. New Horizons will likely be closer to PT1 than our simulation reflects, though, as NASA will be using a portion of its remaining fuel to get closer to its target.

You can also check out NASA’s own New Horizons simulation.

Recent Updates & Changes

In this update we’ve also made it possible to draw trails relative to a body and made additional tweaks and fixes.

In Alpha 15.1, released on June 26th, we updated the look of Ceres based on the latest photos from NASA, added a random asteroid feature, new moons of Pluto, pulsar jets, and improved the look of brown dwarfs. We also re-introduced the ability to customize launch bodies: Hover over bodies in the Add panel then press a number key to assign the body to that launch slot.

Full list of What’s New

 

 

 

Watch a Demo of Exoplanet Detection in Universe Sandbox ²

The video below was created by Eric, an astronomer working on Universe Sandbox ².

He explains how we calculate both radial velocity and normalized light curves, two key components in methods of detecting exoplanets.

You will be able to try out these new features for yourself in an upcoming alpha of Universe Sandbox ².

If you do not yet own Universe Sandbox ², you can buy it now to get instant access to the alpha, as well as free updates up to and including the final release: universesandbox.com/2.