Their pay, age, political leanings and more: 6 Supreme Court questions answered

The complicated and controversial nomination of Brett Kavanaugh to the Supreme Court has prompted a number of questions about the highest court in the land and the lifetime appointments that justices serve once they get confirmed.

Here are some of those burning questions answered.

1. How old are the Supreme Court justices?

The age of Supreme Court justices becomes a factor as soon as they are nominated because they are granted lifetime appointments.

Justices can resign or retire from the bench and some have died while serving.

Here are the ages of the current justices, in ascending order:

Associate Justice Neil Gorsuch, 51 years old Associate Justice Elena Kagan, 58 years old Chief Justice John Roberts, 63 years old Associate Justice Sonia Sotomayor, 64 years old Associate Justice Samuel Alito, 68 years old Associate Justice Clarence Thomas, 70 years old Associate Justice Stephen Breyer, 80 years oldAssociate Justice Ruth Bader Ginsburg, 85 years old

2. Who has been on the Supreme Court the longest?

Of the current batch of sitting justices, Associate Justice Thomas has been on the court the longest, having assumed the seat in October 1991 and serving just shy of 27 years.

The next justice, Ginsburg, took her place on the bench in August 1993.

Justice Breyer took his spot almost exactly a year later in August 1994.

There was a nine-year gap before Chief Justice Roberts took over for Chief Justice William Rehnquist in September 2005.

Justice Alito was appointed less than a year later, in January 2006.

Up next was Justice Sotomayor in August 2009. Justice Kagan took her spot in August 2010.

Justice Gorsuch was the first appointment of the Trump administration. A seat opened after the death of Justice Antonin Scalia. Gorsuch took his spot on the bench in April 2017.

3. Can a Supreme Court justice be impeached?

Yes. But it's only ever happened once, and even in that case, the justice stayed on the bench.Congress can remove a Supreme Court justice if he or she is impeached. In the history of the court, there has only been one justice who was impeached, Samuel Chase, in 1804, but the Senate acquitted the charges so he didn't leave the court, according to the Congressional Research Service.

4. How many appointments do presidents get to make?

There is no set rule regarding the number of presidential appointments because they are dependent on the departure of existing justices.

Presidents John F. Kennedy, Lydon B. Johnson, George H.W. Bush, Bill Clinton, George W. Bush and Barack Obama all made two appointments during their tenure.

Before that, President Ronald Reagan made four appointments during his administration, as did President Richard Nixon.

According to CRS, six presidents only made one appointment and three presidents made no Supreme Court appointments during their time in office.

5. What are the political leanings of the Supreme Court justices?

In recent decades, Supreme Court picks tend to fall along the political lines of the president who nominated them to the court.

What that means now is that justices picked by Republican presidents -- like Thomas, Alito, Roberts, Gorsuch and now potentially Kavanaugh -- tend to rule more conservatively than justices nominated by Democratic presidents -- like Breyer, Ginsburg, Sotomayor and Kagan.

Justice Anthony Kennedy, whose spot Kavanaugh was selected to fill, was largely seen as the swing vote because although he was nominated by Reagan, a 538 analysis found that he tended to vote on the side of the more liberal justices than his conservative brethren.

6. How much do Supreme Court justices make for their salary?

The difference between the associate justices and the chief justice matters when it comes to salary.

The sole chief justice earns more than the other members of the bench.

According to the U.S. Courts system, the chief justice's salary this year is $267,000. The other seven other associate justices earn $255,300.

Those salaries have increased roughly $2,000 to $4,000 per year since 2014.

Associate Justice Thomas is the longest serving justice on the bench, having been appointed by then-President George H.W. Bush in 1991. At the time, the salary for his role was $153,600.

538 reporters Ritchie King, Oliver Roeder and Amelia Thomson-DeVeaux contributed to this report.