5 things to know about the Supreme Court

President Obama plans to announce who his nominee to replace Supreme Court Justice Antonin Scalia, who died unexpectedly on Feb. 13.

Obama says he has selected federal appeals court judge Merrick Garland, the White House confirms.

The Supreme Court is the highest court in the land, a court that can control how we live our lives or if someone can go free or stay behind bars. But what do you really know about the Supreme Court of the United States?

Here are five facts you should know about the Supreme Court:

1. The court is made up of nine justices. Currently, with Scalia's death, there are only eight serving: Chief Justice John Roberts Jr. and Associate Justices Anthony Kennedy, Clarence Thomas, Ruth Bader Ginsburg, Stephen Breyer, Samuel Alito Jr., Sonia Sotomayor and Elena Kagan. There are also three retired associate justices: Sandra Day O'Connor, David Souter and John Paul Stevens.

2. While the justices do not issue decisions every day, they have a large potential caseload. Approximately 7,000 to 8,000 new cases are filed each term. About 80 of those will be allowed a plenary review, with arguments presented by attoeys. Another 100 are disposed of without a review. After the arguments, the court will publish the justices' written opinions and orders, which can thousands of pages long. Some opinions may be revised a dozen times before they are issued. 

3. Oral arguments are open to the public,but there is limited seating. Lines can form well before the opening of court. Seating for a session begins at 9:30 a.m. When court is not hearing arguments, the Supreme Court building is open for tours.

>>Read the Visitor's Guide to Oral Argument

4. Normally each side can present its argument for 30 minutes, and up to 24 cases may be heard at one sitting. Most cases involve a review of a lower court's decision. No jury is present and no witnesses give testimony. Each justice is given a record of previous proceedings and briefs with the arguments from each side. 

5. Famous names have served on the Supreme Court. Thurgood Marshall was the first African-American justice. O'Connor was the first woman. Sotomayor is the first Hispanic Supreme Court justice. William Howard Taft was the only president to also serve on the high court, and he was nominated after he served as president. Other names like John Marshall, Oliver Wendell Holmes and William Brennan may be recognizable from your high school civics class.