Under the supervision of Chief Justice John Roberts of the US Supreme Court, the trial begins at 1 p.m. in the Senate. ET and runs six days a week, including Saturdays, for possibly three to five weeks. The definitive rules for the procedure, including the witness testimony, are still being worked out.
The issue is whether Trump should be removed from office because of his behavior in dealing with Ukraine. That includes a phone call in July in which he appears to have asked the President of Ukraine to investigate former US Vice President Joe Biden, currently a democratic presidential candidate, and his son Hunter's ties with a Ukrainian gas company in exchange for US military assistance
In the December vote, Parliament adopted articles saying that Trump was abusing power and hindering Congress. Both votes were largely over the party boundaries in the Democratically-controlled House, with sixty-seven senators in the Republican-controlled Senate who had to vote to remove the president for removal.
Full coverage of the impeachment hearings can be found here.
Here's how you can follow.
How can I watch?
Different news networks and outlets will stream the events of the day. A number of broadcasters, including PBS and cable news channels Fox News, MSNBC, CNN and C-SPAN, have previously pre-set regular programming to offer live broadcasts from the House that debated articles of deposition, with networks expected to be the same for the Senate trial on Tuesday. (Disclosure: CNET is a division of CBS Interactive, owned by CBS.)
Although it is currently unclear, it is also possible that local broadcasters CBS, ABC and NBC will also broadcast the first day of the hearings.
You can stream the hearing online for free on sites such as C-SPAN 2.
What time does it all start?
The Senate trial starts at 1 p.m. ET on Tuesday.
Who else has been dropped off?
Trump joins Andrew Johnson and Bill Clinton as the third president to be deposed by the House since the constitution was adopted in 1788.
Richard Nixon resigned before the House had the chance to accuse him of his role in the Watergate scandal. Both Clinton and Johnson were acquitted by the Senate in their respective deposition sentences.
What does Trump have to say?
In a six-page letter to House Speaker Nancy Pelosi in December prior to the House vote, Trump destroyed the procedure and said that "more appropriate trial was granted to those accused in the Salem Witch Trials. "
"It is time for you and the very partisan Democrats in Congress to immediately stop this accusation fantasy and go back to work for the American people," wrote the president. "Although I don't expect you to do that, I am writing this letter to you for the purpose of history and to place my thoughts on a permanent and indelible report."
Where is Trump now?
President Trump is currently in Davos, Switzerland, for the World Economic Forum. White House press secretary, Stephanie Grisham, told reporters that he is "regularly informed by staff".
Where can I find out more about deposition?
CBS News has full coverage of the deposition process, investigation and procedures.
Originally published on November 12.
Update, December 18: Adds information about the deposition of votes in the Lower House .
Update January 21: Updated due to Senate trial .
Correction, November 14: An earlier version of this story incorrectly describes Joe Biden. He is a democratic presidential candidate.