Astronomer and UCLA Professor Andrea Ghez has been named a co-winner of the Nobel Prize in physics. She shares the honor with Berkeley colleague Reinhard Genzel and Sir Roger Penrose of Oxford University. Ghez is only the fourth woman to be awarded the Nobel Prize in physics, and she joins Christiane to react to the news.

Before President Trump fell ill, the most talked-about debate issue was his refusal to clearly denounce white supremacy and the Proud Boys. Kristofer Goldsmith is a U.S. Army veteran, having enlisted after 9/11, and he has spent years tracking the efforts of extremist organizations to recruit American soldiers. He explains why white supremacist groups pose a serious danger to democracy.

President Trump, still sick with COVID-19, is back at work in the White House with a skeleton crew. The virus has now infected at least 11 members of the White House staff, and most observers are shocked by the president's continuing disregard for coronavirus protocols. For a reality check on the virus and on governmental responses, Christiane speaks with public health expert Devi Sridhar.

Joe Biden has received regular COVID-19 tests since last week’s debate with President Trump, who is now known to be ill with the virus. To discuss Trump's conduct, the Biden campaign’s concerns, and the effect all this could have on the presidential race, Christiane speaks with former Secretary of Health and Human Services and current Congresswoman Donna Shalala.

During the lengthy investigation into President Trump's relationship with Russia, Robert Mueller’s team was conspicuously tight-lipped. Now, one of Mueller’s top deputies is speaking out. Andrew Weissmann has decades of experience in the Justice Department. In his new book, "Where Law Ends," Weissman argues that Mueller and his team made serious missteps.

To respond to the administration’s policies on Iran, Christiane speaks with Vali Nasr, a former senior adviser at the State Department and current Professor of Middle East Studies and International Affairs at Johns Hopkins University.

Reports on the state of President Trump's health have been conflicting and confounding, with profound implications for national security. To discuss this and to talk substance on foreign policy, Christiane speaks with Elliott Abrams, the State Department's Special Representative for Iran and Venezuela.

History will record the current era as one characterized by a dangerous erosion of truth and trust in government -- concurrent with a global pandemic, economic and environmental collapse, and multinational uprisings. To gain perspective on all of this, Christiane speaks with renowned historian Margaret MacMillan, whose new book "War: How Conflict Shaped Us" is earning respectful reviews.

Do we expect too much of the American president? Political journalist John Dickerson believes so, having interviewed many of the men to have held the office -- including the current occupant. In his New York Times bestseller, Dickerson reminds us of how the responsibility and influence of the office have expanded since its creation-- and the effect of all this on the public's expectations.

British Prime Minister Boris Johnson is one of the few world leaders who truly understands what President Trump faces following his COVID-19 diagnosis. Earlier this year, Johnson was rushed to intensive care due to the virus. Mark Landler of the New York Times joins the program to compare Trump's diagnosis to Johnson's.

This diagnosis is the most serious known health threat to a sitting U.S. president in decades. President Trump’s team says he will continue his duties while recovering, but with 32 days to go before the election, how will this impact the campaign? And what are the constitutional norms for such a situation? Christiane speaks with journalist Ryan Lizza and constitutional scholar Deborah Pearlstein.

When it comes to understanding how coronavirus spreads, most of us have heard about the R number – the average reproduction number of people infected by one other person. But Zeynep Tufekci says it’s more telling to look at a different letter: K. It’s the subject of her latest prescient article in The Atlantic, and she joins Christiane to explain.

President Trump and the First Lady have tested positive for the coronavirus and are now experiencing “mild symptoms” according to the White House. At 74 years old and clinically obese, the president is a high risk patient. Former acting surgeon general Boris Lushniak joins Christiane to explain the medical risks and assess how this infection could have reached the commander in chief.

Like President Trump, Russian President Vladimir Putin initially played down the coronavirus – but his country has the world’s fourth highest number of cases. And when it comes to protecting himself, Putin has been far more rigorous than Trump. Correspondent Matthew Chance joins the show from Moscow with details of Putin’s own protective bubble.

Julián Castro was the only Latino candidate to run for president this election season. He previously served as mayor of San Antonio, Texas and was secretary for housing and urban development under President Obama. Though a strong critic of Biden’s record on immigration, Castro tells Walter Isaacson why he believes the former vice president is the man for the job.

Gloria Steinem has spent a lifetime fighting for women’s rights, and now her story has been adapted into a biopic, "The Glorias." She joins the program to discuss the film and the current political scene, along with veteran director Julie Taymor.

Too hot; jarring; exhausting. These are just some of the ways Republicans have described Tuesday’s debate, offering some rare pointed criticisms of their candidate. What does the Trump inner circle make of it? Media mogul Christopher Ruddy has known President Trump for two decades and joins the program to discuss.

Black History Month begins today in the UK. One person marking it in a unique way is Misan Harriman, who recently made history as the first Black male photographer to shoot the cover of British Vogue. The cover became a defining image of London’s Black Lives Matter protests, and now Harriman's auctioning it off for charity. He joins the show from the auction house Sotheby.

America and the world tuned in last night for the presidential debate--the first between President Donald Trump and former Vice President Joe Biden. The debate became a study in chaos, mostly due to interruptions by President Trump. What did American voters think? To discuss, Christiane speaks with pollster Frank Luntz and Kevin Sheekey, Michael Bloomberg’s former campaign manager.

While foreign policy was barely mentioned in Tuesday’s debate, one country did come up repeatedly: China. Each candidate accused the other of being soft on Beijing. Now, a new report from the House Intelligence Committee warns that Washington is ill-eqipped to counter a rising China. Committee chair Adam Schiff joins the program from D.C. to discuss.