Earlier this summer, the folks behind ScienceDebate.org sent the presidential candidates a list of 20 questions that likely won't garner much airtime in the televised debates this fall. They asked about climate change, mental health, space exploration, vaccinations, antibiotic-resistant superbugs and the future of U.S. energy.

Hillary Clinton and Donald Trump both responded — though Clinton's answers are twice as long and noticeably more detailed — and you can find their full answers here.

Perhaps the starkest contrast between the candidates, scientifically speaking, involves climate change.

That's not entirely surprising. Clinton has embraced the Obama administration's efforts to curb greenhouse gas emissions and slow the effects of global warming and has vowed to push forward in the same direction. Trump repeatedly has said he isn’t “a believer” that humans have played a significant role in the Earth’s changing climate, and he has called the concept of global warming everything from a “hoax” to “bulls—” to a scheme “created by and for the Chinese in order to make U.S. manufacturing non-competitive.” (He later said he was joking about the China tweet).

In his response to the ScienceDebate.org questions, Trump's campaign basically dodged the climate change question, writing that "there is still much that needs to be investigated in the field of 'climate change.'" (Nearly all climate scientists agree that human activity is contributing to the warming of the planet.) Trump wrote that perhaps the nation's "limited financial resources" would be better spent making sure people have clean water, eliminating diseases such as malaria or developing energy sources that reduce dependence on fossil fuels.

Clinton's campaign wrote that "when it comes to climate change, the science is crystal clear. Climate change is an urgent threat and a defining challenge of our time and its impacts are already being felt at home and around the world." Clinton goes on to detail specific goals if she were to take office, such as generating half the nation's electricity from clean energy sources.

Aside from such obvious differences, however, Trump and Clinton seem to have at least a sliver of common ground when it comes to science and energy issues.

"Nuclear power must be an integral part of energy independence for America," Trump responded to one question, calling nuclear "a valuable source of energy."

Clinton wrote that the climate challenges are "too important to limit the tools available in this fight," and that nuclear power "is one of those tools."

Both candidates also appear to support space exploration and vowed to invest in it.

"The cascading effects of a vibrant space program are legion and can have a positive, constructive impact on the pride and direction of this country," Trump wrote.

"We must maintain our nation's leadership in space with a program that balances science, technology and exploration," Clinton wrote, saying she would work to ensure NASA has adequate funding.

Even on vaccines, which Trump previously has suggested might contribute to autism (despite abundant scientific evidence that there is no link), both candidates in the recent survey sounded a similar note.

"We should educate the public on the values of a comprehensive vaccination program," Trump wrote.

Clinton said as president, she would push to "educate parents about vaccines, focusing on their extraordinary track record in saving lives and pointing out the dangers of not vaccinating our children."

In 2008, Democratic nominee Barack Obama and Republican nominee John McCain submitted answers to more than a dozen questions from the same group. In 2012, President Obama and Republican nominee Mitt Romney did the same. You can see their answers here and here.

As of Monday afternoon, the group was still waiting for answers from Libertarian Party candidate Gary Johnson. Green Party candidate Jill Stein submitted her responses, including her belief that "climate change is the greatest existential threat that humanity has ever faced."

Read more: