Under the supervision of Chief Justice John Roberts of the US Supreme Court, the trial is scheduled to begin at 1:00 p.m. in the Senate. ET and run six days a week, including Saturdays, for three to five weeks. The final rules for the procedure, including the approval of witnesses, are still being worked out.
It is controversial whether Trump should be removed from office because of his behavior towards Ukraine. This includes a phone call in July where he appears to have asked the President of Ukraine, former U.S. Vice President Joe Biden, who is currently a Democratic presidential candidate, and his son Hunter's connections to a Ukrainian gas company in exchange for U.S. military aid to investigate
At the December vote, Parliament passed articles saying Trump had abused power and hindered Congress. Both votes were largely bipartisan in the democratically controlled house, with 67 senators in the republican controlled senate having to vote to remove the president to complete the impeachment process.
A full presentation of the impeachment hearings can be found here.
How you can participate.
How can I watch?
Various news channels and outlets broadcast the events of the day live. A number of broadcasters, including PBS and the cable news channels Fox News, MSNBC, CNN and C-SPAN, had previously allowed regular programs to offer live broadcasts of the house's impeachment articles. The broadcasters should also do this for the Senate trial on Tuesday. (Disclosure: CNET is a division of CBS Interactive, which is owned by CBS.)
Although currently unclear, local broadcasters CBS, ABC and NBC may also broadcast on the first day of the hearings.
You can stream the hearing online for free to websites like C-SPAN 2.
When does it all start?
The trial against the Senate is scheduled to begin at 1:00 p.m. ET on Tuesday.
Who else was charged?
Trump joins Andrew Johnson and Bill Clinton as the third president who has been indicted by parliament since the constitution was adopted in 1788.
Richard Nixon resigned before Parliament had the opportunity to indict him for his role in the Watergate scandal. Both Clinton and Johnson were acquitted by the Senate in their impeachment proceedings.
What does Trump have to say?
In a six-page letter to the House Speaker Nancy Pelosi in December prior to the House vote, Trump broke the process and stated that "the accused were granted a more appropriate trial in the Salem witch trials."
"It is time for you and the high party Democrats in Congress to immediately stop this impeachment fantasy and work for the American people again," wrote the President. "I have no expectation that you will do this, but I am writing this letter for the purpose of history and to put my thoughts on a permanent and indelible record."
Where's Trump right now?
President Trump is currently in Davos for the World Economic Forum in Switzerland. The White House press secretary, Stephanie Grisham, told reporters that he was "regularly staffed".
Where can I find out more about impeachment?
CBS News fully covers the impeachment, investigation and process.
Originally published November 12.
Updated December 18: Adds information to vote on impeachment in the House of Representatives .
Update, January 21: Updated to reflect the process of the Senate .
Correction, November 14: An earlier version of this story incorrectly described Joe Biden. He is a democratic presidential candidate.